Screening and Characterisation of Keratin-Degrading Bacillus sp. from Feather Waste

Aim: This study focuses on the screening and characterisation of keratin-degrading Bacillus species from feather waste. Methods: Nine bacteria were isolated from feather waste obtained from a poultry layout at Egbeda local government secretariat, Ibadan, Nigeria. These bacteria were grown in basal medium with feather as primary source of carbon, nitrogen, sulfur and energy. Feather degrading bacteria were screened for both proteolytic activity and keratin degradation on skimmed milk agar and keratin azure medium respectively. They were also screened for their ability to degrade other keratin substrates such as hair and nail. Results: Three of the isolates with higher feather degradation levels also showed high proteolytic activity and release of azure dye. They were selected and identified phenotypically and genotypically using 16S rRNA sequencing as Bacillus licheniformis-K51, Bacillus subtilis-K50 and Bacillus sp.-K53. The bacteria were capable of degrading other keratin-containing substrates such as nail and hair. Bacillus subtilis-K50 and Bacillus licheniformis-K51 showed significant difference (P) in degradation among the three different keratin sources used yielding higher degradation with feather as keratin source with respective optical densities of 0.07 and 0.11 followed by hair and least in nails with optical densities of 0.05 and 0.07 respectively. Highest degradation of all the three keratin substrates was observed in Bacillus licheniformis-K51. Conclusion: The three isolated bacteria possess the ability to degrade keratin and utilize feather as keratin substrate. As a result, these can be considered as potential candidates for degradation and utilization of feather keratin.

Evaluation of resistance to natural poisoning by Amorimia septentrionalis in goats which had received sodium monofluoroacetate degrading bacteria / Avaliação da resistência à intoxicação natural por Amorimia septentrionalis em caprinos que receberam bactérias degradadoras de monofluoroacetato de sódio

Amorimia septentrionalis is an important sodium monofluoroacetate (MFA) containing plant that causes sudden death in ruminants in northeastern Brazil. MFA degrading bacteria are being used in the prevention against poisoning by this plant. The aim of this study was to evaluate if goats which had per os received MFA degrading bacteria remained resistant when exposed to natural poisoning by A. septentrionalis. Eighteen goats were randomly distributed into three groups: the goats of Group 1 previously received, during 40 days, a solution containing the bacteria Ralstonia sp. and Burkholderia sp., those goats in the Group 2 received the bacteria Paenibacillus sp. and Cupriavidus sp. and goats from Group 3 did not receive any bacteria. After the administration period, during 60 days, the animals of all groups were released to graze on a one hectare paddock, with significant amount of A. septentrionalis. They were observed daily for the spontaneous consumption of A. septentrionalis leaves and the occurrence of clinical signs of poisoning or sudden death. Goats from all groups consumed significant amounts of A. septentrionalis during the experimental period. Goats that did not receive MFA-degrading bacteria (Group 3) became sick and died from the 25th to the 27th day of the experiment, whereas the goats of the groups that received MFA-degrading bacteria showed only clinical sings when A. septentrionalis regrowth after the 55th day of the experiment. The days elapsed from field observation to death of Group 3 goats (25.5±0.9 days) were significantly lower (p<0.05) than Group 1 (58.6±1.3 days) and Group 2 (57.8±1.5 days). Thus, it can be concluded that administration of MFA degrading bacteria increases the resistance to natural poisoning by A. septentrionalis.(AU)

Amorimia septentrionalis que contém monofluoroacetato de sódio (MFA) é responsável pela ocorrência de mortes súbitas em ruminantes no nordeste do Brasil. Bactérias degradadoras desse composto estão sendo utilizadas na prevenção contra a intoxicação por essa planta. O objetivo deste estudo foi avaliar se caprinos que receberam, via oral, bactérias degradadoras de MFA permaneciam resistentes quando expostos a intoxicação natural por A. septentrionalis. Dezoito caprinos foram divididos em três grupos, os caprinos do Grupo 1 receberam anteriormente, durante 40 dias, uma solução contendo as bactérias Ralstonia sp. e Burkholderia sp., os do Grupo 2 receberam, também por 40 dias as bactérias Paenibacillus sp. e Cupriavidus sp. e os do Grupo 3 não receberam nenhuma bactéria. Após o período de administração, durante 60 dias, os animais de todos os grupos foram soltos para pastar em um piquete de um hectare, que apresentava uma quantidade significativa da planta. Diariamente eles foram observados quanto ao consumo espontâneo das folhas de A. septentrionalis e quanto à presença de sinais clínicos de intoxicação ou morte. Os caprinos de todos os grupos consumiram quantidades significantes da planta durante o período experimental. Os caprinos que não receberam as bactérias degradantes de MFA (Grupo 3) adoeceram e morreram entre o 25º e o 27º dia de experimento, enquanto que os que receberam as bactérias degradantes de MFA (Grupo 1 e 2) só apresentaram sinais clínicos no 55º dia de experimento, o que coincidiu com a rebrota da planta. Os dias transcorridos desde a observação a campo até a morte dos caprinos do Grupo 3 (25,5±0,9 dias) foram significativamente menores (p<0,05) que os do Grupo 1 (58,6±1,3 dias) e do Grupo 2 (57,8±1,5 dias). Com isso pode-se concluir que a administração de bactérias degradadoras de MFA aumenta à resistência a intoxicação natural por A. septentrionalis.(AU)

Biodegradation of the fungicide carbendazim by bacteria from Coriandrum sativum L rhizosphere / Biodegradação do agrotóxico carbendazim por bactérias da rizosfera de Coriandrum sativum L

The biocidal agrochemicals commonly used in agriculture can remain in the soil, affecting the environmental conditions and causing serious risks to health. Knowing that soil microorganisms, especially those from the rhizosphere, can degrade environmental xenobiotics, it was evaluated the potential of bacteria isolated from Coriandrum sativum L. rhizosphere to biodegrade carbendazim (MBC), a fungicide extensively used by agriculturists from rural farming communities in Manaus, Amazonas. Cultures carried out in medium containing carbendazim as a sole carbon source enabled the isolation of 80 bacteria, in the established conditions. Assays to determine degradation potential allowed the selection of the two elite isolates identified as Stenotrophomonas sp. and Ochrobactrum sp. Quantitative assays with each strain individually or in consortium, were carried out using minimal salt medium added with carbendazim (250 µg mL-1) and incubated at 30°C, under agitation (125 rpm) for 21 days. Samples used in the biodegradation test were HPLC analyzed for final fungicide quantitation. The Stenotrophomonas sp. strain was more efficient (68.9%) to degrade carbendazim and showed no toxicity in tests with Artemia salina.

Agrotóxicos são comumente utilizados na produção agrícola, podendo persistir no solo, afetar a qualidade do ambiente e causar sérios riscos à saúde. Sabendo-se que micro-organismos do solo, principalmente aqueles da rizosfera, podem degradar produtos xenobióticos avaliou-se o potencial de bactérias isoladas da rizosfera de Coriandrum sativum L. em degradar carbendazim, um fungicida usado extensivamente em comunidades de agricultores rurais em Manaus, Amazonas. Procedimentos de cultivo em meio, contendo carbendazim como única fonte de carbono, mostraram que 80 bactérias cresceram nas condições estabelecidas. Ensaios de eficiência de degradação permitiram a seleção dos dois melhores isolados que foram identificados como Stenotrophomonas sp. e Ochrobactrum sp. Os ensaios quantitativos, com cada cepa individualmente e com as duas em consórcio, foram conduzidos em meio mínimo contendo sais, acrescido de carbendazim (250 µg mL-1) e incubados a 30°C, 125 rpm, por 21 dias. A quantificação final do fungicida nas amostras do ensaio de biodegradação foi realizada em HPLC. A linhagem Stenotrophomonas sp. apresentou maior eficiência, degradando 68,9% do total de carbendazim e não apresentou toxicidade nos testes realizados com Artemia salina.

Aerobic cyanide degradation by bacterial isolates from cassava factory wastewater

Ten bacterial strains that utilize cyanide (CN) as a nitrogen source were isolated from cassava factory wastewater after enrichment in a liquid media containing sodium cyanide (1 mM) and glucose (0.2% w/v). The strains could tolerate and grow in cyanide concentrations of up to 5 mM. Increased cyanide levels in the media caused an extension of lag phase in the bacterial growth indicating that they need some period of acclimatisation. The rate of cyanide removal by the strains depends on the initial cyanide and glucose concentrations. When initial cyanide and glucose concentrations were increased up to 5 mM, cyanide removal rate increased up to 63 and 61 per cent by Bacillus pumilus and Pseudomonas putida. Metabolic products such as ammonia and formate were detected in culture supernatants, suggesting a direct hydrolytic pathway without an intermediate formamide. The study clearly demonstrates the potential of aerobic treatment with cyanide degrading bacteria for cyanide removal in cassava factory wastewaters.

Isolation, characterization and identification of bacteria from coolant oils.

Coolants are hydrocarbons, used to lubricate parts of machines for smooth performance. While in use, a coolant quickly gets contaminated with foreign materials, making it less effective and unpleasant odors are developed due to microbial action. Hence coolants need to be replaced frequently. The expense of disposing used coolants and replacing it with fresh coolants adds significantly to the manufacturing cost. The present study is focused on isolation, identification and characterization of coolant oil contaminating bacteria as an initial step to solve these contamination problems. Used and unused samples of coolant were collected from oil stations, auto mechanic workshops and steel industry for the isolation of the contaminants. Ten dominant bacterial isolates of the genus Pseudomonas, Staphylococcus, Micrococcus, Salmonella, Cellobiococcus and Pneumonia were identified by morphology, biochemical tests and PIB tool. Isolates were subjected to four different media, various pH and temperatures for characterization of optimal conditions of growth. Pseudomonas pseudomallei, Micrococcus luteus 3, Micrococcus varians and Salmonella ferlac were observed in mineral, synthetic and aerobic media, Staphylococcus hyicus, Cellobiococcus species and Staphylococcus intermedius in synthetic and aerobic fermentation media and Pseudomonas cepacia, Pseudomonas piketti in mineral salt and aerobic fermentation media. The ten isolates showed optimal growth at different temperatures between 20°C and 90°C and different pH, ranging from acidic to alkaline. In conclusion, the used coolants harbor hazardous pathogens such as Pseudomonas species which multiply rapidly and survive high temperatures. These isolates could be targeted for further studies on development of antidotes as a solution to the coolant contamination problems.

Peptidolytic microbial community of methanogenic reactors from two modified UASBs of brewery industries

We studied the peptide-degrading anaerobic communities of methanogenic reactors from two mesophilic full-scale modified upflow anaerobic sludge blanket (UASB) reactors treating brewery wastewater in Colombia. Most probable number (MPN) counts varied between 7.1 x 10(8) and 6.6 x 10(9) bacteria/g volatile suspended solids VSS (Methanogenic Reactor 1) and 7.2 x 10(6) and 6.4 x 10(7) bacteria/g (VSS) (Methanogenic Reactor 2). Metabolites detected in the highest positive MPN dilutions in both reactors were mostly acetate, propionate, isovalerate and, in some cases, negligible concentrations of butyrate. Using the highest positive dilutions of MPN counts, 50 dominant strains were isolated from both reactors, and 12 strains were selected for sequencing their 16S rRNA gene based on their phenotypic characteristics. The small-subunit rRNA gene sequences indicated that these strains were affiliated to the families Propionibacteriaceae, Clostridiaceae and Syntrophomonadaceae in the low G + C gram-positive group and Desulfovibrio spp. in the class d-Proteobacteria. The main metabolites detected in the highest positive dilutions of MPN and the presence of Syntrophomonadaceae indicate the effect of the syntrophic associations on the bioconversion of these substrates in methanogenic reactors. Additionally, the potential utilization of external electron acceptors for the complete degradation of amino acids by Clostridium strains confirms the relevance of these acceptors in the transformation of peptides and amino acids in these systems.

Hydrocarbon-degradation by isolate Pseudomonas lundensis UTAR FPE2

In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL) also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

Study on the Bioemulsifier Produced by a Hydrocarbon- degrading Strain T7-2 and Its Physic-chemical Properties / 微生物学通报

A low-temperature hydrocarbon-degrading strain T7-2, isolated from sea-mud of Bohai polluted area and identified as Rhodococcus erythropolis, was found to produce an extracellular, nondialyzable emul- sifying agent (referred to as bioemulsifier) when grew with hexadecane as carbon source. The results showed that, this bioemulsifier which could remarkably emulsify hydrocarbons such as diesel oil, is consisted of three parts-carbohydrates, lipids and proteins, the proportion of which was 55.43:31.24:12.65. The mono- saccharide compositions were identified as mannose and rhamnose; the lipid compositions included de- canoic acid, lauric acid, hexadecanoic acid and stearic acid, and the protein constituents were composed of sixteen amino acids. Besides, according to the study of the physic-chemical properties of the bioemulsifier, it possesses the obvious advantages of character stability, high function efficiency and wide adaptation range, therefore this bioemulsifier is believed to have extensive application values for bioremediation of marine oil pollution, petroleum exploitation and etc.

Isolation and Degrading Characteristics of a Phenol-degrading Bacterial Strain with High Efficiency / 微生物学通报

A high efficiency phenol-degrading bacterial strain PS1 was isolated from the drainage ditch of chemical laboratory of East China Institute of Technology.PS1 is a coccus,Gram negative and can live on phenol as its sole carbon and energy source.PS1 to identified as a strain of Raoultella sp.by 16S rRNA gene sequence analysis,which can degrade and tolerate more than 3500mg/L phenol.When phenol concentration is 500mg/L and 1000mg/L,PS1 can completely degrade it in 22 h and 32h,respectively.And while it is between 1500mg/L～3000mg/L,all phenol can be degraded by PS1 in 32h～50h.When phenol concentration is 2500mg/L,the phenol-degrading rate is the biggest and can reach to 78.1mg/h.The optimum growth and phenol-degrading conditions were obtained by orthogonal experiment,which are 25℃,pH6.5,glucose concentration 500mg/L and 20℃,pH7.0,glucose concentration 500mg/L,respectively.