Search results for: bacterial isolates

Authors: Gimhani Madhushika Hewayalage, Thilini Ariyadasa, Sanja Gunawardena

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In Sri Lanka, the largest contribution for the industrial export earnings is governed by textile and apparel industry. However, this industry generates huge quantities of effluent consists of unfixed dyes which enhance the effluent colour and toxicity thereby leading towards environmental pollution. Therefore, the effluent should properly be treated prior to the release into the environment. The biological technique has now captured much attention as an environmental-friendly and cost-competitive effluent decolourization method due to the drawbacks of physical and chemical treatment techniques. The present study has focused on identifying dye decolourizing potential of several bacterial isolates obtained from the effluent of the local textile industry. Yellow EXF, Red EXF, Blue EXF, Nova Black WNN and Nylosan-Rhodamine-EB dyes have been selected for the study to represent different chromophore groups such as Azo and Xanthene. The rates of decolorization of each dye have been investigated by employing distinct bacterial isolates. Bacterial isolate which exhibited effective dye decolorizing potential was identified as Proteus mirabilis using 16S rRNA gene sequencing analysis. The high decolorizing rates of identified bacterial strain indicate its potential applicability in the treatment of dye-containing wastewaters.

Keywords: azo, bacterial, biological, decolourization, xanthene

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Authors: Hai Chi, Ibrahim Mehmeti, Kirill Ovchinnikov, Hegle Holo, Ingolf F. Nes, Dzung B. Diep

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By using a panel of multiple indicator strains of different bacterial species and genera, we screened a large collection of bacterial isolates (over 1800 isolates) derived from raw milk, for bacteriocin producers with broad inhibition spectra (BIS). Fourteen isolates with BIS were identified, and by 16S rDNA sequencing they were found to belong to Lactococcus garvieae (10 isolates) and Enterococcus feacalis (4 isolates). Further analysis of the ten L. garvieae isolates revealed that they were very similar, if not identical, to each other in metabolic and genetic terms: they had the same fermentation profile on different types of sugars, repetitive sequence-based PCR (rep-PCR) DNA pattern as well as they all had the same inhibition profile towards over 50 isolates of different species. The bacteriocin activity from one of the L. garvieae isolates was assessed further. The bacteriocin which was termed garvicin KS, was found to be heatstable and proteinase-labile and its inhibition spectrum contained many distantly related genera of Firmicutes, comprising most lactic acid bacteria (LAB) as well as problematic species of Bacillus, Listeria, Streptococcus and Staphylococcus and their antibiotic resistant derivatives (e.g. VRE, MRSA). Taken together, the results indicate that this is a potent bacteriocin from L. garvieae and that its very broad inhibition spectrum can be a very useful property for use in food preservation as well as in infection treatments caused by gram-positive pathogens and their antibiotic-derivatives.

Keywords: bacteriocin, lactic acid bacteria, Lactococcus garvieae, antibiotics resistance

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Authors: E. Osazee, L. U. Bashir

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This study was conducted at the Department of Biological Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria, to determine the effects of different weights of cow dung on indigenous bacterial isolates in remediation of crude oil contaminated soils. The soil (1kg) was contaminated with 20g of crude oil and this was treated with three (40g, 80g and 120g) weights of cow dung. The soils were amended after two weeks of crude oil contamination. Soil samples were collected from the plastic bags for microbiological analyses. The isolates were cultured to test their ability to grow on crude oil. The ability of the isolates to utilize the crude oil was determined using media dilution technique. Bacteria such as Proteus mirabilis, Bacillus lacterosporus, Morganella morganii, Serratia marcescens and Bacillus alvei were isolated. The variables measured were heterotrophic bacterial populations, hydrocarbon utilizing bacterial populations and the percentage of crude oil degraded in the soils. Data collected were subjected to analysis of variance (ANOVA). Results obtained indicated that all the different weights of cow dung showed appreciable effect in crude oil decontamination. Based on the findings of the experiments, it could be deduced that 120g of cow dung promoted higher degradation of hydrocarbons. Thus, it should be recommended for remediation of crude oil contaminated soil in the study area.

Keywords: crude oil, cow dung, amendment, bioremediation, decontamination

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Authors: M. J. Norashirene, Y. Zakiah, S. Nurdiana, I. Nur Hilwani, M. H. Siti Khairiyah, M. J. Muhamad Arif

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In this study, six bacterial isolates of a slightly thermophilic organism from the Sg. Klah hot spring, Malaysia were successfully isolated and designated as M7T55D1, M7T55D2, M7T55D3, M7T53D1, M7T53D2 and M7T53D3 respectively. The bacterial isolates were screened for their cellulose hydrolytic ability on Carboxymethlycellulose agar medium. The isolated bacterial strains were identified morphologically, biochemically and molecularly with the aid of 16S rDNA sequencing. All of the bacteria showed their optimum growth at a slightly alkaline pH of 7.5 with a temperature of 55°C. All strains were Gram-negative, non-spore forming type, strictly aerobic, catalase-positive and oxidase-positive with the ability to produce thermostable cellulase. Based on BLASTn results, bacterial isolates of M7T55D2 and M7T53D1 gave the highest homology (97%) with similarity to Tepidimonas ignava while isolates M7T55D1, M7T55D3, M7T53D2 and M7T53D3 showed their closest homology (97%-98%) with Tepidimonas thermarum. These cellulolytic thermophiles might have a commercial potential to produce valuable thermostable cellulase.

Keywords: cellulase, cellulolytic, thermophiles, 16S rDNA gene

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Authors: Mohammad Aladwan, Adelia Skripova

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Bioremediation aspects of crude oil-polluted fields can be achieved by isolation and identification of bacterial species from oil-contaminated soil in order to choose the most active isolates and increase the strength of others. In this study, oil-degrading bacteria were isolated and identified from oil-contaminated soil samples in northeastern Jordan. The bacterial growth count (CFU/g) was between 1.06×10⁵ and 0.75×10⁹. Eighty-two bacterial isolates were characterized by their morphology and biochemical tests. The identified bacterial genera included: Klebsiella, Staphylococcus, Citrobacter, Lactobacillus, Alcaligenes, Pseudomonas, Hafnia, Micrococcus, Rhodococcus, Serratia, Enterobacter, Bacillus, Salmonella, Mycobacterium, Corynebacterium, and Acetobacter. Molecular identification of a universal primer 16S rDNA gene was used to identify four bacterial isolates: Microbacterium esteraromaticum strain L20, Pseudomonas stutzeri strain 13636M, Klebsilla pneumoniae, and uncultured Klebsilla sp., known as new strains. Our results indicate that their specific oil-degrading bacteria isolates might have a high strength of oil degradation from oil-contaminated sites. Staphylococcus intermedius (75%), Corynebacterium xerosis (75%), and Pseudomonas fluorescens (50%) showed a high growth rate on different types of hydrocarbons, such as crude oil, toluene, naphthalene, and hexane. In addition, monooxygenase and catechol 2,3-dioxygenase were detected in 17 bacterial isolates, indicating their superior hydrocarbon degradation potential. Total petroleum hydrocarbons were analyzed using gas chromatography for soil samples. Soil samples M5, M7, and M8 showed the highest levels (43,645, 47,805, and 45,991 ppm, respectively), and M4 had the lowest level (7,514 ppm). All soil samples were analyzed for heavy metal contamination (Cu, Cd, Mn, Zn, and Pb). Site M7 contains the highest levels of Cu, Mn, and Pb, while Site M8 contains the highest levels of Mn and Zn. In the future, these isolates of bacteria can be used for the cleanup of oil-contaminated soil.

Keywords: bioremediation, 16S rDNA gene, oil-degrading bacteria, hydrocarbons

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Authors: Geeta Negi, Pankaj, Anjana Srivastava, Anita Sharma

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In the present study, the presence of endosulfan, imidacloprid, carbendazim, in the soil /vegetables/cereals and water samples was observed in agriculture fields of Uttarakhand. In view of biodegradation of these pesticides, nine bacterial isolates were recovered from the soil samples of the fields which tolerated endosulfan, imidacloprid, carbendazim from 100 to 200 µg/ml. Three bacterial consortia used for in vitro bioremediation experiments were three bacterial isolates for carbendazim, imidacloprid and endosulfan, respectively. Maximum degradation (87 and 83%) of α and β endosulfan respectively was observed in soil slurry by consortium. Degradation of Imidacloprid and carbendazim under similar conditions was 88.4 and 77.5% respectively. FT-IR analysis of biodegraded samples of pesticides in liquid media showed stretching of various bonds. GC-MS of biodegraded endosulfan sample in soil slurry showed the presence of non-toxic intermediates. A pot trial with Bacterial treatments lowered down the uptake of pesticides in onion plants.

Keywords: biodegradation, carbendazim, consortium, endosulfan

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Authors: Shayma Munqith Al-Baker, Fadhl Ahmed Saeed Al-Gasha’a, Samira Hamid Hanash, Ahmed Ali Al-Hazmi

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A total of 200 samples (180 fecal materials and 20 organ samples) were collected from (5 different poultry farms, 10 local poultry shops, 5 houses poultry, 5 Eggs stores shops and 5 hand slaughters centers) in Ibb city, Yemen, 2014. According to morphological, cultural, as well as biochemical characterization and serological tests, 59 29.5% isolates were identified as Salmonella spp. and all Salmonella isolates were categorized by serotype, which comprised of, 37 62.71% Salmonella Typhimurium serovar, 21 35.59%. Salmonella Enteritidis serovar and 11.69% Salmonella Heidelberg serovar. Antibiotic sensitivity test was done for bacterial isolates and the results showed there were clear differences in antibiotic resistant. Antimicrobial susceptibility of the isolates varies as follows: Ofloxacin 79.66%, Ciprofloxacin 67.80%, Colistin 59.32% and Gentamycin 52.54%. All of isolates were resistant to Erythromycin, Penicillin and Lincomycin. Antibacterial activity was done for both aqueous and ethanol extracts of Dodonaea viscosa plant by using well and disc diffusion assay. The results indicated that well diffusion assay had best results than disc diffusion assay, the highest inhibition zone was 22 mm for well diffusion and 15 mm for disc diffusion assay, the results observed that ethanol extract had best antibacterial effect than aqueous extract which the percentage of bacterial isolates affected with ethanol extract was 71.19% comparing with aqueous extract 28.81% by using disc diffusion assay, while the percentage of bacterial isolates affected with ethanol extract was 88.13% comparing with aqueous extract 52.54% by using will diffusion assay.

Keywords: Salmonella spp, Dodonaea viscosa, antimicrobial and salmonellosis

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Authors: Baharuddin Patandjengi, A. Pabborong, T. Kuswinanti

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Bacterial ring rot caused by a gram-positive Coryneform bacterium Corynebacterium michiganensis subsp. sepedonicus is an important disease on potato crops in the world. The disease still belongs to an A1 quarantine pathogen in Indonesia, although it was found in West Java since 2013. The objective of this study was to know the presence of bacterial ring rot in four potato district areas in South Sulawesi. Infected samples were collected from potato fields and storage warehouses in Enrekang, Gowa, Jeneponto and Bantaeng districts. Potato tuber samples were cut and observed their vasiculer vessels and the bacterial ooze was used for isolation on Nutrient Agar and Nutrient Broth–Yeast extract medium. Bacterial isolates were then morphologically and physiologically characterized. A patogenicity test on eggplant and molecular characterization using PCR with specific primer for Cms (50F and Cms 50 R) was revealed for further identification. The results showed that Cms has become widespread in four districts of South Sulawesi. The bacterial ringrot disease incidence in these districts was reached above 30 %. All of 14 bacterial isolates that identified before using standard methods of EPPO, showed DNA band in size of 224 bp in PCR test, which indicated positively belong to C. michiganensis subsp. sepedonicus.

Keywords: bacterial ring rot, clavibacter michiganensis pv. sepedonicus, PCR, potato

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Authors: Hardik Goswami, Gayatri Swarnakar

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-Mastitis disease has been known as one of the most costly diseases of dairy cattle and observed as an inflammatory disease of cow and buffalo udder. Mastitis badly affected animal health, quality of milk and economics of milk production along with cause’s great economic loss. Bacteria have been representing the most common etiological agents of mastitis. The antibiotic sensitivity test was important to attain accurate treatment of mastitis. The aim of present research work was to explore prevalence and antibiotic susceptibility pattern of bacterial isolates recovered from cow and buffalo clinical mastitis milk sample. During the period of April 2010 to April 2014, total 1487 clinical mastitis milk samples of cow and buffalo were tested to check the prevalence of mastitis causing bacterial isolates. Milk samples were collected aseptically from the udder at the time of morning milking. The most prevalent bacterial isolates were Staphylococcus aureus (24.34%) followed by coliform bacteria (15.87%), coagulase negative Staphylococcus aureus (13.85%), non-coliform bacteria (13.05%), mixed infection (12.51%), Streptococcus spp. (10.96%). Out of 1487, 140 (9.42%) mastitis milk samples showed no growth on culture media. Identification of bacteria made on the basis of Standard Microbial features and procedures. Antibiotic susceptibility of bacterial isolates was investigated by Kirby-Bauer disk diffusion method. In vitro Antibiotic susceptibility test of bacterial isolates revealed higher sensitivity to Gentamicin (74.6%), Ciprofloxacin (62.1%) and Amikacin (59.4%). The lower susceptibility was shown to Amoxicillin (21.6%), Erythromycin (26.4%) and Ceftizoxime (29.9%). Antibiotic sensitivity pattern revealed Gentamicin are the possible effective antibiotic against the major prevalent mastitis pathogens. Present research work would be helpful in increase production, quality and quantity of milk, increase annual income of dairy owners and improve health of cow and buffaloes.

Keywords: antibiotic, buffalo, cow, mastitis, prevalence

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Authors: Shaghayegh Rafatpanah, Mehrnaz Rad, Ahmad Reza Movassaghi, Javad Khoshnegah

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The purpose of the present study was to investigate the prevalence of isolation, antimicrobial susceptibility and ERIC-PCR typing of staphylococci species from dogs with pyoderma. The study animals were 61 clinical cases of Iranian domestic dogs with the first-time pyoderma. The prevalence of pyoderma was significantly higher amongst adult (odds Ratio: 0.21; p=0.001) large breed (odds Ratio: 2.42; p=0.002)dogs. There was no difference in prevalence of pyoderma in male and females (odds Ratio: 1.27; p= 0.337). The 'head, face and pinna' and 'trunk' were the most affected lesion regions, each with 19 cases (26.76%). An identifiable underlying disease was present in 52 (85.24%) of the dogs. Bacterial species were recovered from 43 of the 61 (70.49%) studied animals. No isolates were recovered from 18 studied dogs. The most frequently recovered bacterial genus was Staphylococcus (32/43 isolates, 74.41%) including S. epidermidis (22/43 isolates, 51.16%), S. aureus (7/43 isolates, 16.27%) and S. pseudintermedius (3/43 isolates, 6.97%). Staphylococci species resistance was most commonly seen against amoxicillin (94.11%), penicillin (83.35%), and ampicillin (76.47%). Resistant to cephalexin and cefoxitin was 5.88% and 2.94%, respectively. A total of 27 of the staphylococci isolated (84.37 %) were resistant to at least one antimicrobial agent, and 19 isolates (59.37%) were resistant to three or more antimicrobial drugs. There were no significant differences in the prevalence of resistance between the staphylococci isolated from cases of superficial and deep pyoderma. ERIC-PCR results revealed 19 different patterns among 22 isolates of S. epidermidis and 7 isolates of S. aureus.

Keywords: dog, pyoderma, Staphylococcus, Staphylococcus epidermidis, Iran

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Authors: Zahid Rehman, TorOve Leiknes

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Quorum sensing (QS) is the process by which bacteria communicate with each other through small signaling molecules, such as N-acylhomoserine lactones (AHLs). Also, certain bacteria have the ability to degrade AHL molecules by a process referred to as quorum quenching (QQ); therefore, QQ can be used to control bacterial infections and biofilm formation. In this study, we aimed to identify new species of bacteria with QQ activities. To achieve this, sediments from Red Sea were collected either in the close vicinity of Sea grass or from area with no vegetation. From these samples, we isolated 72 bacterial strains and tested their ability to degrade/inactivate AHL molecules. Chromobacterium violaceum based bioassay was used in initial screening of isolates for QQ activity. The QQ activity of the positive isolates was further confirmed and quantified by employing liquid chromatography and mass spectrometry. These analyses showed that isolated bacterial strain could degrade AHL molecules with different acyl chain length and modifications. Sequencing of 16S-rRNA genes of positive isolates revealed that they belong to three different genera. Specifically, two isolates belong to genus Erythrobacter, four to Labrenzia and one isolate belongs to Bacterioplanes. Time course experiment showed that isolate belonging to genus Erythrobacter could degrade AHLs faster than other isolates. Furthermore, these isolates were tested for their ability to inhibit formation of biofilm and degradation of 3OXO-C12 AHLs produced by P. aeruginosa PAO1. Our results showed that isolate VG12 is better at controlling biofilm formation. This aligns with the ability of VG12 to cause at least 10-fold reduction in the amount of different AHLs tested.

Keywords: quorum sensing, biofilm, quorum quenching, anti-biofouling

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Authors: Solomon Gebremariam, Mulugeta Naizigi, Aregawi Haileselassie

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Background: Knowledge of the pattern of bacterial isolates and their antimicrobial susceptibility is crucial for guiding empirical treatment and infection prevention and control measures. Objective: The aim of this study was to analyze the pattern of bacterial isolates and their susceptibility patterns from various specimens. Methods: Retrospectively, a total of 1067 microbiological culture results that were isolated, characterized, and identified by standard microbiological methods and whose antibiotic susceptibility was determined using CLSI guidelines between 2017 and 2019 were retrieved and analyzed. Data were entered and analyzed using the Stata release 10.1 statistical package. Result: The positivity rate of culture was 26.04% (419/1609). The most common bacteria isolated were S. aureus 23.8% (94), E. coli 15.1% (60), Klebsiella pneumonia 14.1% (56), Pseudomonas aeruginosa 8.5% (34), and CONS 7.3% (29). S. aureus and CONS showed a high (58.1% - 96.2%) rate of resistance to most antibiotics tested. They were less resistant to Vancomycin which is 18.6% (13/70) and 11.8% (2/17), respectively. Similarly, the resistance of E. coli, Klebsella pneumonia, and Pseudomonas aeruginosa was high (69.4% - 100%) to most antibiotics. They were less resistant to Ciprofloxacilin, which is 41.1% (23/56), 19.2% (10/52), and 16.1% (5/31), respectively. Conclusion: This study has shown that there is a high rate of antibiotic resistance among bacterial isolates in this hospital. A combination of Vancomycin and Ciprofloxacin should be considered in the choice of antibiotics for empirical treatment of suspected infections due to S. aureus, CONS, E. coli, Klebsiella pneumonia, Pseudomonas such as in infections within hospital setup.

Keywords: antimicrobial, resistance, bacteria, hospital

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Authors: Afroza Parvin, Md. Mahmudul Hasan, Md. Rokunozzaman, Papon Debnath

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The effluents of textile industries have considerable amounts of heavy metals, causing potential microbial metal loads if discharged into the environment without treatment. Aim: In this present study, both lactose and non-lactose fermenting bacterial isolates were isolated from textile industrial effluents of a specific region of Bangladesh, named Savar, to compare and understand the load of heavy metals in these microorganisms determining the effects of heavy metal resistance properties on antibiotic resistance. Methods: Five different textile industrial canals of Savar were selected, and effluent samples were collected in 2016 between June to August. Total bacterial colony (TBC) was counted for day 1 to day 5 for 10-6 dilution of samples to 10-10 dilution. All the isolates were isolated and selected using 4 differential media, and tested for the determination of minimum inhibitory concentration (MIC) of heavy metals and antibiotic susceptibility test with plate assay method and modified Kirby-Bauer disc diffusion method, respectively. To detect the combined effect of heavy metals and antibiotics, a binary exposure experiment was performed, and to understand the plasmid profiling plasmid DNA was extracted by alkaline lysis method of some selective isolates. Results: Most of the cases, the colony forming units (CFU) per plate for 50 ul diluted sample were uncountable at 10-6 dilution, however, countable for 10-10 dilution and it didn’t vary much from canal to canal. A total of 50 Shigella, 50 Salmonella, and 100 E.coli (Escherichia coli) like bacterial isolates were selected for this study where the MIC was less than or equal to 0.6 mM for 100% Shigella and Salmonella like isolates, however, only 3% E. coli like isolates had the same MIC for nickel (Ni). The MIC for chromium (Cr) was less than or equal to 2.0 mM for 16% Shigella, 20% Salmonella, and 17% E. coli like isolates. Around 60% of both Shigella and Salmonella, but only 20% of E.coli like isolates had a MIC of less than or equal to 1.2 mM for lead (Pb). The most prevalent resistant pattern for azithromycin (AZM) for Shigella and Salmonella like isolates was found 38% and 48%, respectively; however, for E.coli like isolates, the highest pattern (36%) was found for sulfamethoxazole-trimethoprim (SXT). In the binary exposure experiment, antibiotic zone of inhibition was mostly increased in the presence of heavy metals for all types of isolates. The highest sized plasmid was found 21 Kb and 14 Kb for lactose and non-lactose fermenting isolates, respectively. Conclusion: Microbial resistance to antibiotics and metal ions, has potential health hazards because these traits are generally associated with transmissible plasmids. Microorganisms resistant to antibiotics and tolerant to metals appear as a result of exposure to metal-contaminated environments.

Keywords: antibiotics, effluents, heavy metals, minimum inhibitory concentration, resistance

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Authors: Maryam Beiranvand, Sajad Yaghoubi

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Background: Some microbes can colonize plants’ inner tissues without causing obvious damage and can even produce useful bioactive substances. In the present study, the diversity of the endophytic bacteria associated with medicinal plants from Iran was investigated by culturing techniques, molecular gene identification, as well as measuring them for antibacterial activity. Results: In the spring season from 2013 to 2014, 35 herb pharmacology samples were collected, sterilized, meshed, and then cultured on selective media culture. A total of 199 endophytic bacteria were successfully isolated from 35 tissue cultures of medical plants, and sixty-seven out of 199 bacterial isolates were subjected to identification by the 16S rRNA gene sequence analysis method. Based on the sequence similarity gene and phylogenetic analyses, these isolates were grouped into five classes, fourteen orders, seventeen families, twenty-one genera, and forty strains. The most abundant group of endophytic bacteria was actinobacterial, consisting of thirty-two (47%) out of 67 bacterial isolates. Ten (22.3%) out of 67 bacterial isolates remained unidentified and classified at the genus level. The signature of the 16S rRNA gene formed a distinct line in a phylogenetic tree showing that they might be new species of bacteria. One (5.2%) out of 67 bacterial isolates was still not well categorized. Forty-two out of 67 strains were candidates for antimicrobial activity tests. Nineteen (45%) out of 42 strains showed antimicrobial activity multidrug resistance (MDR); thirteen (68%) out of 19 strains were allocated to classes actinobacteria. Four (21%) out of 19 strains belonged to the Bacillaceae family, one (5.2%) out of 19 strains was the Paenibacillaceae family, and one (5.2%) out of 19 strains belonged to the Pseudomonadaceae family. The other twenty-three strains did not show inhibitory activities. Conclusions: Our research showed a high-level phylogenetic diversity and the intoxicating antibiotic activity of endophytic bacteria in the herb pharmacology of Iran.

Keywords: Antibacterial activity, endophytic bacteria, multidrug-resistant bacteria, whole genom sequencing

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Authors: Maryam Beiranvand, Sajad Yaghoubi

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Background: Some microbes can colonize plants’ inner tissues without causing obvious damage and can even produce useful bioactive substances. In the present study, the diversity of the endophytic bacteria associated with medicinal plants from Iran was investigated by culturing techniques, molecular gene identification, as well as measuring them for antibacterial activity. Results: In the spring season from 2013 to 2014, 35 herb pharmacology samples were collected, sterilized, meshed, and then cultured on selective media culture. A total of 199 endophytic bacteria were successfully isolated from 35 tissue cultures of medical plants, and sixty-seven out of 199 bacterial isolates were subjected to identification by the 16S rRNA gene sequence analysis method. Based on the sequence similarity gene and phylogenetic analyses, these isolates were grouped into five classes, fourteen orders, seventeen families, twenty-one genera, and forty strains. The most abundant group of endophytic bacteria was actinobacterial, consisting of thirty-two (47%) out of 67 bacterial isolates. Ten (22.3%) out of 67 bacterial isolates remained unidentified and classified at the genus level. The signature of the 16S rRNA gene formed a distinct line in a phylogenetic tree showing that they might be new species of bacteria. One (5.2%) out of 67 bacterial isolates was still not well categorized. Forty-two out of 67 strains were candidates for antimicrobial activity tests. Nineteen (45%) out of 42 strains showed antimicrobial activity multidrug-resistance (MDR); thirteen (68%) out of 19 strains were allocated to classes actinobacteria. Four (21%) out of 19 strains belonged to the Bacillaceae family, one (5.2%) out of 19 strains was the Paenibacillaceae family, and one (5.2%) out of 19 strains belonged to the Pseudomonadaceae family. The other twenty-three strains did not show inhibitory activities. Conclusions: Our research showed a high-level phylogenetic diversity and the intoxicating antibiotic activity of endophytic bacteria in the herb pharmacology of Iran.

Keywords: medical plant, endophytic bacteria, antimicrobial activity, whole genome sequencing analysis

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Authors: Nurcihan Hacioglu, Cigdem Gul, Murat Tosunoglu

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In this article, the antibiogram and heavy metal resistance profile of the bacteria isolated from total 34 studied animals (Pelophylax ridibundus = 12, Mauremys rivulata = 14, Natrix natrix = 8) captured around the Biga Stream, are described. There was no database information on antibiogram and heavy metal resistance profile of bacteria from these area’s amphibians and reptiles. In this study, a total of 200 bacteria were successfully isolated from cloaca and oral samples of the aquatic amphibians and reptiles as well as from the water sample. According to Jaccard’s similarity index, the degree of similarity in the bacterial flora was quite high among the amphibian and reptile species under examination, whereas it was different from the bacterial diversity in the water sample. The most frequent isolates were A. hydrophila (31.5%), B. pseudomallei (8.5%), and C. freundii (7%). The total numbers of bacteria obtained were as follows: 45 in P. ridibundus, 45 in N. natrix 30 in M. rivulata, and 80 in the water sample. The result showed that cefmetazole was the most effective antibiotic to control the bacteria isolated in this study and that approximately 93.33% of the bacterial isolates were sensitive to this antibiotic. The Multiple Antibiotic Resistances (MAR) index indicated that P. ridibundus (0.95) > N. natrix (0.89) > M. rivulata (0.39). Furthermore, all the tested heavy metals (Pb+2, Cu+2, Cr+3, and Mn+2) inhibit the growth of the bacterial isolates at different rates. Therefore, it indicated that the water source of the animals was contaminated with both antibiotic residues and heavy metals.

Keywords: bacteriological quality, amphibian, reptile, antibiotic, heavy metal resistance

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Authors: Ilknur Tuncer, Nihayet Bizsel

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The studies in bacterial diversity and antimicrobial resistance in coastal areas are important to understand the variability in the community structures and metabolic activities. In the present study, antimicrobial susceptibility and phylogenetic analysis of bacteria isolated from stations with different depths and influenced by terrestrial and marine fluxes in eastern Aegean Sea were illustrated. 51% of the isolates were found as resistant and 14% showed high MAR index indicating the high-risk sources of contamination in the environment. The resistance and the intermediate levels and high MAR index of the study area were 38–60%, 11–38% and 0–40%, respectively. According to 16S rRNA gene analysis, it was found that the isolates belonged to two phyla Firmicutes and Gammaproteobacteria with the genera Bacillus, Halomonas, Oceanobacillus, Photobacterium, Pseudoalteromonas, Psychrobacter, and Vibrio. 47% of Bacillus strains which were dominant among all isolates were resistant. In addition to phylogenetically diverse bacteria, the variability in resistance, intermediate and high MAR index levels of the study area indicated the effect of geographical differences.

Keywords: bacterial diversity, multiple antibiotic resistance, 16S rRNA genes, Aegean Sea

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Authors: Ilknur Tuncer, Nihayet Bizsel

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The scarcity of research in bacterial diversity and antimicrobial resistance in coastal environments as in Turkish coasts leads to difficulties in developing efficient monitoring and management programs. In the present study, biogeochemical analysis of sediments and antimicrobial susceptibility analysis of bacteria in Izmir Bay, eastern Aegean Sea under high anthropogenic pressure were aimed in summer period when anthropogenic input was maximum and at intertidal zone where the first terrigenious contact occurred for aquatic environment. Geochemical content of the intertidal zone of Izmir Bay was firstly illustrated such that total and organic carbon, nitrogen and phosphorus contents were high and the grain size distribution varied as sand and gravel. Bacterial diversity and antibiotic resistance were also firstly given for Izmir Bay. Antimicrobially assayed isolates underlined the multiple resistance in the inner, middle and outer bays with overall 19% high MAR (multiple antibiotic resistance) index. Phylogenetic analysis of 16S rRNA gene sequences indicated that 67 % of isolates belonged to the genus Bacillus and the rest included the families Alteromonadaceae, Bacillaceae, Exiguobacteriaceae, Halomonadaceae, Planococcaceae, and Staphylococcaceae.

Keywords: bacterial phylogeny, multiple antibiotic resistance, 16S rRNA genes, Izmir Bay, Aegean Sea

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Authors: Minhas Alam, Muhammad Hidayat Rasool, Mohsin Khurshid, Bilal Aslam

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Acinetobacter baumannii is a notorious bacterial pathogen that is an emerging nightmare in clinical settings and is mainly involved in severe nosocomial infections. However, the data related to carbapenem-resistant A. baumannii (CRAB) from veterinary settings is limited, especially in developing countries like Pakistan. To investigate the genetic diversity and molecular basis of carbapenem resistance in Acinetobacter baumannii isolates from Cattle, a total of 1960 samples were collected from cattle from Punjab, Pakistan. The isolates were analyzed by routine microbiological procedures and confirmed by polymerase chain reaction (PCR). The isolates were further screened for antimicrobial susceptibility and the presence of multiple antimicrobial-resistant determinants by PCR. Multilocus sequence typing (MLST) was performed. The results of the current study revealed that the overall prevalence of A. baumannii in cattle was 3.28% (65/1980). Among cattle 27.7% (18/65) were found CRAB strains. The CRAB isolates harbor class D β- lactamases genes, e-g, blaOXA-23 and blaOXA-51, 94.4% (17/18). CRAB isolates carry class B β- lactamases gene blaIMP, and only one isolate carries the blaNDM-1 gene. The MLST results of CRAB isolates from cattle demonstrated 5 STs and one new ST. The commonly found sequence types in CRAB isolates were ST2 (n=10, 55.5%), followed by ST642 (n=5, 27.8%) and ST600 & ST889 (n=1, 5.55%). The presence of CRAB isolates in cattle indicates an alarming situation in Punjab, Pakistan. Immediate control measures should be taken to stop the transmission of CRAB isolates within cattle, to the environment, and to clinical settings.

Keywords: acinetobacter baumannii, carbapenemases, veterinary, drug resistance

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Authors: Natesan Balasubramanian, Palpandi Pounpandi, Venkatraman Thamil Priya, Vellasamy Shanmugaiah, Karubbiah Balakrishnan, Mandayam Anandam Thirunarayan

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Streptococcus agalactiae is commonly known as Group B Streptococcus (GBS) and it is the most common cause of life-threatening bacterial infection. GBS first considered as a veterinary pathogen causing mastitis in cattle later becomes a human pathogen for severe neonatal infections. In this present study, a total of 20 new clinical isolates of S. agalactiae were collected from male (6) and female patient (14) with different age group. The isolates were from Urinary tract infection (UTI), blood, pus and eye ulcer. All the 20 S. agalactiae isolates has clear hemolysis properties on blood agar medium and were identified by serogrouping and MALTI-TOF-MS analysis. Antibiotic susceptibility/resistance test was performed for 20 S. agalactiae isolates, further phenotypic resistance pattern was observed for tetracycline, vancomycin, ampicillin and penicillin. Genotypically we found two antibiotic resistance genes such as Betalactem antibiotic resistance gene (Tem) (70%) and tetracycline resistance gene Tet(O) 15% in our isolates. Six virulence factors encoding genes were performed by PCR in twenty GBS isolates, cfb gene (100%), followed by, cylE(90.47%), lmp(85.7%), bca(71.42%), rib (38%) and low frequency in bac gene (4.76%) were determined. Most of the S. agalactiae isolates produced strong biofilm in the polystyrene surface (hydrophobic), and low-level biofilm formation was found in glass tube (hydrophilic) surface. lytR is secreted protein and localized in bacterial cell wall, extra cellular membrane, and cytoplasm. In silico docking studies were performed for lytR protein with four antibiofilm compounds, including a peptide (PR39) with the docking study showed peptide has strong interaction followed by ellagic acid and interaction length is 2.95, 2.97 and 2.95 A°. In ligand EGCGO10 and O11 two atoms intract with lytR (Leu271), with binding bond affinity length is 3.24 and 3.14. The aminoacid Leu 271 is act as an impartant aminoacid, since ellagic acid and EGCG interact with same aminoacid.

Keywords: antibiotics, biofilms, clinical isolates, S. agalactiae, virulence

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Authors: Abeer M. Algeblawi

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Fifteen isolates of Agrobacterium tumefaciens were obtained from crown gall samples collected from six locations (Tripoli, Alzahra, Ain-Zara, Alzawia, Alazezia in Libya) from Grape (Vitis vinifera L.), Pear (Pyrus communis L.), Peach (Prunus persica L.) and Alexandria in Egypt from Guava (Psidium guajava L.) trees, Artichoke (Cynara cardunculus L.) and Sugar beet (Beta vulgaris L.). Total DNA was extracted from the eight isolates as well as the identification of six isolates used into Polymerase Chain Reaction (PCR) analysis and Random Amplified Polymorphic DNA (RAPD) technique were used. High similarity (55.5%) was observed among the eight A. tumefaciens isolates (Agro1, Agro2, Agro3, Agro4, Agro5, Agro6, Agro7, and Agro8). The PCR amplification products were resulting from the use of two specific primers (virD2A-virD2C). Analysis induction six isolates of A. tumefaciens obtained from different hosts. A visible band was specific to A. tumefaciens of (220 bp, 224 bp) and 338 bp produced with total DNA extracted from bacterial cells.

Keywords: Agrobacterium tumefaciens, crown gall, identification, molecular characterization, PCR, RAPD

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Authors: Essam A. Makky, Siti H. Mohd Rasdi, J. B. Al-Dabbagh, G. F. Najmuldeen

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The synthesis of silver nano particles (SNPs) extensively studied by using chemical and physical methods. Here, the biological methods were used and give benefits in research field in the aspect of very low cost (from waste to wealth) and safe time as well. The study aims to isolate and exploit the microbial power in the production of industrially important by-products in nano-size with high economic value, to extract highly valuable materials from hazardous waste, to quantify nano particle size, and characterization of SNPs by X-Ray Diffraction (XRD) analysis. Disposal X-ray films were used as substrate because it consumes about 1000 tons of total silver chemically produced worldwide annually. This silver is being wasted when these films are used and disposed. Different bacterial isolates were obtained from various sources. Silver was extracted as nano particles by microbial power degradation from disposal X-ray film as the sole carbon source for ten days incubation period in darkness. The protein content was done and all the samples were analyzed using XRD, to characterize of silver (Ag) nano particles size in the form of silver nitrite. Bacterial isolates CL4C showed the average size of SNPs about 19.53 nm, GL7 showed average size about 52.35 nm and JF Outer 2A (PDA) showed 13.52 nm. All bacterial isolates partially identified using Gram’s reaction and the results obtained exhibited that belonging to Bacillus sp.

Keywords: nanotechnology, bioremediation, disposal X-ray film, nanoparticle, waste, XRD

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Authors: Ali Bahkali, Rayan Yousef Booq, Mohammad Khiyami

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Soil samples were collected from five different regions in the Kingdom of Saudi Arabia. Microbiological methods included dilution methods and pour plates to isolate and purify bacteria soil. The ability of isolates to develop biopolymer was investigated on petri dishes containing elements and substance concentrations stimulating developing biopolymer. Fluorescent stains, Nile red and Nile blue were used to stain the bacterial cells developing biopolymers. In addition, Sudan black was used to detect biopolymers in bacterial cells. The isolates which developed biopolymers were identified based on their gene sequence of 1 6sRNA and their ability to grow and synthesize PHAs on mineral medium supplemented with 1% dates molasses as the only carbon source under nitrogen limitation. During the study 293 bacterial isolates were isolated and detected. Through the initial survey on the petri dishes, 84 isolates showed the ability to develop biopolymers. These bacterial colonies developed a pink color due to accumulation of the biopolymers in the cells. Twenty-three isolates were able to grow on dates molasses, three strains of which showed the ability to accumulate biopolymers. These strains included Bacillus sp., Ralstonia sp. and Microbacterium sp. They were detected by Nile blue A stain with fluorescence microscopy (OLYMPUS IX 51). Among the isolated strains Ralstonia sp. was selected after its ability to grow on molasses dates in the presence of a limited nitrogen source was detected. The optimum conditions for formation of biopolymers by isolated strains were investigated. Conditions studied included, best incubation duration (2 days), temperature (30°C) and pH (7-8). The maximum PHB production was raised by 1% (v1v) when using concentrations of dates molasses 1, 2, 3, 4 and 5% in MSM. The best inoculated with 1% old inoculum (1= OD). The ideal extraction method of PHA and PHB proved to be 0.4% sodium hypochlorite solution, producing a quantity of polymer 98.79% of the cell's dry weight. The maximum PHB production was 1.79 g/L recorded by Ralstonia sp. after 48 h, while it was 1.40 g/L produced by R.eutropha ATCC 17697 after 48 h.

Keywords: bacteria forming polyhydroxyalkanoate, detection, molecular, Saudi Arabia

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Authors: Bandana Saikia, Ashok Bhattacharyya

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Endophytic microbes and their metabolites positively impact overall plant health, which may have a potential implication in agriculture. In the present study, 177 bacterial endophytes and 57 fungal endophytes were isolated, with the highest recovery rate from tomato roots. A maximum of 112 endophytes were isolated during monsoon, followed by 64 isolates and 58 isolates isolated during pre-monsoon and post-monsoon periods, respectively, indicating the rich diversity in bacterial and fungal endophytes of tomato crops from different locations of Assam, India. Further, the endophytes were evaluated for their antagonistic potential against Fusarium oxysporum f. sp. lycopersici. Fungal endophytic isolate AAUTLF (Endophytic Fungi of Tomato Leaf from Assam Agricultural University, Assam, India area) and bacterial endophyte D1B (Endophytic bacteria of tomato from Dhemiji, India district) showed the highest antifungal activity against the pathogen both in vitro and in vivo. Based on 5.8 rDNA sequence analysis of fungal and 16S rDNA sequence of bacteria endophytes, the most effective fungal and bacterial isolates against FOL were identified as Trichoderma asperellum AAUTLF and Stenotrophomonas maltophilia D1B, respectively. The isolates showed an antagonistic effect against Fusarium oxysporum f.sp. lycopersici in-vitro and reduced the disease index of Fusarium wilt in tomatoes by 64.4% under pot conditions. Trichoderma asperellum AAUTLF produced an antifungal compound viz., 6-pentyl-2H-pyran-2-one, which also possesses growth-promoting characteristics. The bacteria Stenotrophomonas maltophilia D1B produced antifungal compounds, including benzothiazole, oleic acid, phenylacetic acid, and 3-(Hydroxy-phenyl-methyl)-2,3-dimethyl-octan-4-one. This would be of high importance for the source of antagonistic strains and biocontrol of tomato Fusarium wilt, as well as other plant fungal diseases.

Keywords: root endophytes, Stemotrophomonas, Trichoderma, benzothiazole, 6-pentyl-2H-pyran-2-one

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Authors: Alisha Akya, Afsaneh salami

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Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections. One of the major concerns for the treatment of P. aeruginosa infections is its resistant to a variety of antibiotics. The purpose of this study was to assess the dissemination of p. aeruginosa isolates obtained from major hospitals in Kermanshah, west of Iran. Materials and Methods: Antibiotic susceptibility testing was performed using the minimal inhibitory concentrations. Mettalo-beta-lactamase was investigated using the double disk diffusion (DDST) test and PCR. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE). Results: The 60 P. aeruginosa isolates, 30 (50%) were resistant to gentamicin, 38 (63/3%) to piperacilin, 42 (70%) to ceftazidime, and 45 (75%) to cefepime. Twenty-nine (48/3%) isolates were MBLs producer based on the DDST test. Five (8/3%) isolates were positive for VIM gene and 4 of them were from burn specimens. PFGE analysis among MBLs producers revealed 12 distinct genotype patterns. A pattern covering the highest number of strains was determined as the dominant clone. Conclusions: Our study showed that P. aeruginosa strains can be spread between patients in hospitals or acquired from different environmental sources. P. aeruginosa isolates were highly resistant to antibiotics and, therefore, the susceptibility of isolates to antibiotics should be tested before treatment. Given the clinical significance of MBLs producing isolates, identification of these organisms is essential in the hospitals in order to get a better therapeutic response and control of bacterial dissemination.

Keywords: clonal dissemination, mettalo-beta-lactamase, Pseudomonas aeruginosa, PFGE

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Authors: Isa Usman Balan, Umar Aliyu, Ahmad Tijjani Muhammed

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The laboratory scale experiment was conducted to determine the phytochemical constituents and antibacterial activities of epiphytic neem leaves (Tapinanthusdodoneifolius) extracts on some selected clinical isolates. The samples were collected using polythene bags to avoid unnecessary contamination of the plants, and they were collected from the old site garden of the BUK. The phytochemical screening and antibacterial test were carried out in the Chemistry and Biology laboratory, respectively at Bayero University Kano (BUK). The result obtained showed that carbohydrates, glycosides, steroids, alkaloids, phenol, saponins and flavonoids are present in the ethanolic extract. However, chloroform extract showed only glycosides, phenols, and carbohydrates. Furthermore, there was no significant difference between the ethanolic extracts and bacterial isolates (p<0.05).

Keywords: phytochemical screening, antibacterial, clinical isolates, epiphytic neem leaves, Tapinanthus dodoneifolius

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Authors: C. E. Ihejirika, M. I. Nwachukwu, R. F. Njoku-Tony, O. C. Ihejirika, U. O. Enwereuzoh, E. O. Imo, D. C. Ashiegbu

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Disposal of industrial solid wastes in the environment is a major environmental challenge. This study investigated the effects of calcium carbide waste dumpsites on soil quality. Soil samples were collected with hand auger from three different dumpsites at varying depths and made into composite samples. Samples were subjected to standard analytical procedures. pH varied from 10.38 to 8.28, nitrate from 5.6mg/kg to 9.3mg/kg, phosphate from 8.8mg/kg to 12.3mg/kg, calcium carbide reduced from 10% to to 3%. Calcium carbide was absent in control soil samples. Bacterial counts from dumpsites ranged from 1.8 x 105cfu/g - 2.5 x 105cfu/g while fungal ranged from 0.8 x 103cfu/g - 1.4 x 103cfu/g. Bacterial isolates included Pseudomonas spp, Flavobacterium spp, and Achromobacter spp, while fungal isolates include Penicillium notatum, Aspergillus niger, and Rhizopus stolonifer. No organism was isolated from the dumpsites at soil depth of 0-15 cm, while there were isolates from other soil depths. Toxicity might be due to alkaline condition of the dumpsite. Calcium carbide might be bactericidal and fungicidal leading to cellular physiology, growth retardation, death, general loss of biodiversity and reduction of ecosystem processes. Detoxification of calcium carbide waste before disposal on soil might be the best option in management.

Keywords: biodiversity, calcium-carbide, denitrification, toxicity

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Authors: Abdul Matin, Muazzama Akhtar, Shahid Nisar, Saddaf Mazzar, Umer Rashid

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Antibiotic resistance is an increasing concern worldwide now a day. Neisseria gonorrhea and Staphylococcus aureus are known to cause major human sexually transmitted and respiratory diseases respectively. Nanotechnology is an emerging discipline and its application in various fields especially in medical sciences is gigantic. In the present study, we synthesized multi-walled carbon nanotubes (MWNTs) using acid oxidation method and solubilized MWNTs were with length predominantly >500 nm and diameters ranging from 40 to 50 nm. The locally synthesized MWNTs were used against gram positive and negative bacteria to determine their impact on bacterial growth. Clinical isolates of Neisseria gonorrhea (isolate: 4C-11) and Staphylococcus aureus (isolate: 38541) were obtained from local hospital and normally cultured in LB broth at 37°C. Both clinical strains can be obtained on request from University of Gujarat. Spectophometric assay was performed to determine the impact of MWNTs on bacterial growth in vitro. To determine the effect of MWTNs on test organisms, various concentration of MWNTs were used and recorded observation on various time intervals to understand the growth inhibition pattern. Our results demonstrated that MWNTs exhibited toxic effects to Staphylococcus aureus while showed very limited growth inhibition to Neisseria gonorrhea, which suggests the resistant potential of Neisseria against nanoparticles. Our results clearly demonstrate the gradual decrease in bacterial numbers with passage of time when compared with control. Maximum bacterial inhibition was observed at maximum concentration (50 µg/ml). Our future work will include further characterization and mode of action of our locally synthesized MWNTs. In conclusion, we investigated and reported for the first time the inhibitory potential of locally synthesized MWNTs on local clinical isolates of Staphylococcus aureus and Neisseria gonorrhea.

Keywords: antibacterial activity, multi walled carbon nanotubes, Neisseria gonorrhea, spectrophotometer assay, Staphylococcus aureus

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Authors: Mokgadi Miranda Hlongwane, Ntebogeng Sharon Mokgalaka, Felix Dapare Dakora

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Lessertia (L.) frutescens (syn. Sutherlandia frutescens) is a leguminous medicinal plant indigenous to South Africa. Traditionally, L. frutescens has been used to treat cancer, diabetes, epilepsy, fever, HIV, stomach problems, wounds and other ailments. This legume is endemic to the Cape fynbos, with large populations occurring wild and cultivated in the Cape Florist Region. Its widespread distribution in the Western Cape, Northern Cape, Eastern Cape and Kwazulu-Natal is linked to its increased use as a phytomedicine in the treatment of various diseases by traditional healers. The frequent harvesting of field plants for use as a medicine has made it necessary to undertake studies towards the conservation of Lessertia frutescens. As a legume, this species can form root nodules and fix atmospheric N₂ when in symbiosis with soil bacteria called rhizobia. So far, however, few studies (if any) have been done on the efficacy and diversity of native bacterial symbionts nodulating L. frutescens in South Africa. The aim of this project was to isolate and characterize L. frutescens-nodulating bacteria from five different locations in the Western Cape Province. This was done by trapping soil rhizobia using rhizosphere soil suspension to inoculate L. frutescens seedlings growing in sterilized sand and receiving sterile N-free Hoagland nutrient solution under glasshouse conditions. At 60 days after planting, root nodules were harvested from L. frutescens plants, surface-sterilized, macerated, and streaked on yeast mannitol agar (YMA) plates and incubated at 28 ˚C for observation of bacterial growth. The majority of isolates were slow-growers that took 6-14 days to appear on YMA plates. However, seven isolates were fast-growers, taking 2-4 days to appear on YMA plates. Single-colony cultures of the isolates were assessed for their ability to nodulate L. frutescens as a homologous host under glasshouse conditions. Of the 92 bacterial isolates tested, 63 elicited nodule formation on L. frutescens. Symbiotic effectiveness varied markedly between and among test isolates. There were also significant (p≤0.005) differences in nodulation, shoot biomass, photosynthetic rates, leaf transpiration and stomatal conductance of L. frutescens plants inoculated with the test isolates, which is an indication of their functional diversity.

Keywords: lessertia frutescens, nodulating, rhizobia, symbiotic effectiveness

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Authors: Ngonidzashe Mangoma, Caroline Marigold Sebata

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The release of cyanide-rich effluents from gold mines, and other industries, into the environment, is a global concern considering the well-known metabolic effects of cyanide in all forms of life. Such effluents need to be treated to remove cyanide, among other pollutants, before their disposal. This study aimed at investigating the possible use of bacteria in the biological removal of cyanide from cyanide-rich effluents. Firstly, cyanide-degrading bacteria were isolated from gold mine effluents and characterised. The isolates were then tested for their ability to grow in the presence of cyanide and their tolerance to increasing levels of the compound. To evaluate each isolate’s cyanide-degrading activities, isolates were grown in the simulated and actual effluent, and a titrimetric method was used to quantify residual cyanide over a number of days. Cyanide degradation efficiency (DE) was then calculated for each isolate. Identification of positive isolates involved 16S rRNA gene amplification and sequence analysis through BLAST. Six cyanide-utilising bacterial strains were isolated. Two of the isolates were identified as Klebsiella spp. while the other two were shown to be different strains of Clostridium bifermentans. All isolates showed normal growth in the presence of cyanide, with growth being inhibited at 700 mg/L cyanide and beyond. Cyanide degradation efficiency for all isolates in the simulated effluent ranged from 79% to 97%. All isolates were able to remove cyanide from actual gold mine effluent with very high DE values (90 – 94%) being recorded. Isolates obtained in this study were able to efficiently remove cyanide from both simulated and actual effluent. This observation clearly demonstrates the feasibility of the biological removal of cyanide from cyanide-rich gold mine effluents and should, therefore, motivate research towards the possible large-scale application of this technology.

Keywords: cyanide effluent, bioremediation, Clostridium bifermentans, Klebsiella spp, environment

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