Degradation of bisphenol A by Bacillus pumilus isolated from kimchi, a traditionally fermented food

Bisphenol A contamination in aquatic environments: a review of sources, environmental concerns, and microbial remediation

The production of polycarbonate, a high-performance transparent plastic, employs bisphenol A, which is a prominent endocrine-disrupting compound. Polycarbonates are frequently used in the manufacturing of food, bottles, storage containers for newborns, and beverage packaging materials. Global production of BPA in 2022 was estimated to be in the region of 10 million tonnes. About 65-70% of all bisphenol A is used to make polycarbonate plastics. Bisphenol A leaches from improperly disposed plastic items and enters the environment through wastewater from plastic-producing industries, contaminating, sediments, surface water, and ground water. The concentration BPA in industrial and domestic wastewater ranges from 16 to 1465 ng/L while in surface water it has been detected 170-3113 ng/L. Wastewater treatment can be highly effective at removing BPA, giving reductions of 91-98%. Regardless, the remaining 2-9% of BPA will continue through to the environment, with low levels of BPA commonly observed in surface water and sediment in the USA and Europe. The health effects of BPA have been the subject of prolonged public and scientific debate, with PubMed listing more than 17,000 scientific papers as of 2023. Bisphenol A poses environmental and health hazards in aquatic systems, affecting ecosystems and human health. While several studies have revealed its presence in aqueous streams, environmentally sound technologies should be explored for its removal from the contaminated environment. Concern is mostly related to its estrogen-like activity, although it can interact with other receptor systems as an endocrine-disrupting chemical. Present review article encompasses the updated information on sources, environmental concerns, and sustainable remediation techniques for bisphenol A removal from aquatic ecosystems, discussing gaps, constraints, and future research requirements.

Degradation of Bisphenol A by Bacillus subtilis P74 Isolated from Traditional Fermented Soybean Foods

Bisphenol A (BPA), one of the most widely used plasticizers, is an endocrine-disrupting chemical that is released from plastic products. The aim of this study was to screen and characterize bacteria with excellent BPA-degrading abilities for application in foods. BPA degradation ability was confirmed in 127 of 129 bacterial strains that were isolated from fermented soybean foods. Among the strains, B. subtilis P74, which showed the highest BPA degradation performance, degraded 97.2% of 10 mg/L of BPA within 9 h. This strain not only showed a fairly stable degradation performance (min > 88.2%) over a wide range of temperatures (30-45 °C) and pH (5.0-9.0) but also exhibited a degradation of 63% against high concentrations of BPA (80 mg/L). The metabolites generated during the degradation were analyzed using high-performance liquid chromatography-mass spectrometry, and predicted degradation pathways are tentatively proposed. Finally, the application of this strain to soybean fermentation was conducted to confirm its applicability in food.

A novel antimicrobial peptide YS12 isolated from Bacillus velezensis CBSYS12 exerts anti-biofilm properties against drug-resistant bacteria

Nowadays, the abuse of antibiotics has led to the rise of multi-drug-resistant bacteria. Antimicrobial peptides (AMPs), with broad-spectrum antimicrobial activity have attracted considerable attention as possible alternatives to traditional antibiotics. In this work, we aimed to evaluate the antimicrobial and anti-biofilm activity of an antimicrobial peptide designed as YS12 derived from Bacillus velezensis CBSYS12. The strain CBSYS12 was isolated from Korean food kimchi and purified followed by ultrafiltration and sequential chromatographic methodology. Hereafter, Tricine SDS-PAGE revealed a single protein band of around 3.3 kDa that was further confirmed in situ inhibitory activity of the gel. A similar molecular weight (~ 3348.4 Da) protein also appeared in MALDI-TOF confirming the purity and homogeneity of peptide YS12. Intriguingly, YS12 revealed a strong antimicrobial activity with a minimum inhibitory concentration (MIC) value ranging from 6 to 12 μg/ml for both Gram-positive and Gram-negative bacteria, such as E. coli, P. aeruginosa, MRSA 4-5, VRE 82, and M. smegmatis. We also determined the mode of action of the peptide against pathogenic microorganisms using different fluorescent dyes. In addition, the anti-biofilm assay demonstrated that peptide YS12 was able to inhibit biofilm formation  around 80% for both bacterial strains E. coli and P. aeruginosa at 80 µg/ml. Notably, YS12 exhibited a greater biofilm eradication activity than commercial antibiotics. In summary, our study proposed that peptide YS12 may be used as a promising therapeutic agent to overcome drug and biofilm-related infections.

Mechanisms of BPA Degradation and Toxicity Resistance in Rhodococcus equi

Bisphenol A (BPA) pollution poses an increasingly serious problem. BPA has been detected in a variety of environmental media and human tissues. Microbial degradation is an effective method of environmental BPA remediation. However, BPA is also biotoxic to microorganisms. In this study, Rhodococcus equi DSSKP-R-001 (R-001) was used to degrade BPA, and the effects of BPA on the growth metabolism, gene expression patterns, and toxicity-resistance mechanisms of Rhodococcus equi were analyzed. The results showed that R-001 degraded 51.2% of 5 mg/L BPA and that 40 mg/L BPA was the maximum BPA concentration tolerated by strain R-001. Cytochrome P450 monooxygenase and multicopper oxidases played key roles in BPA degradation. However, BPA was toxic to strain R-001, exhibiting nonlinear inhibitory effects on the growth and metabolism of this bacterium. R-001 bacterial biomass, total protein content, and ATP content exhibited V-shaped trends as BPA concentration increased. The toxic effects of BPA included the downregulation of R-001 genes related to glycolysis/gluconeogenesis, pentose phosphate metabolism, and glyoxylate and dicarboxylate metabolism. Genes involved in aspects of the BPA-resistance response, such as base excision repair, osmoprotectant transport, iron-complex transport, and some energy metabolisms, were upregulated to mitigate the loss of energy associated with BPA exposure. This study helped to clarify the bacterial mechanisms involved in BPA biodegradation and toxicity resistance, and our results provide a theoretical basis for the application of strain R-001 in BPA pollution treatments.

Bioremediation of a salty petrochemical wastewater containing bisphenol A by a novel indigenous Pseudomonas pseudoalcaligenes

One novel indigenous halotolerant, Pseudomonas sp, with high potential for bisphenol A (BPA) biodegradation was isolated from an outlet of petrochemical wastewater in Iran. The optimal temperature and pH for degradation of BPA by this strain were 30 °C and 7, respectively. This strain was able to decrease COD (chemical oxygen demand) of basal salt medium containing 300 mg L^-1 BPA as sole carbon source and 40 g L^-1 NaCl from 655.2 to 109.2 mg L^-1 (about 83% decrease) after 36 h. The bacterium degraded 56.3 (19%), 202.43 (67%), 288.86 (96%) and 300 mg L^-1 (100%) BPA in basal salt medium containing 300 mg L^-1 BPA and 40 g L^-1 NaCl within 12, 18, 24 and 36 h, respectively. In addition, this strain could degrade phenol (100 mg L^-1) and BPA (300 mg L^-1) in salty petrochemical wastewater within 24 h, completely. In batch fermentation of petrochemical wastewater using this strain higher growth and phenol (100 mg L^-1), BPA (372 mg L^-1) removal within 6 h were achieved. High performance liquid chromatography (HPLC) and gas chromatography mass spectrometry (GC/MS) analysis revealed several intermediates during the BPA degradation process. These intermediates were identified as 4-hydroxybenzaldehyde, 4-hydroxyacetophenone, 4-hydroxyphenylacetate, M-hydroxymandelic acid, 2-phenylpropane-1,2-diol, 2-phenyl-2-propanol and lactic acid. The possible BPA-biodegradation pathway based on the identified metabolites and in agreement with recorded pathway in KEGG database was proposed. Preliminary 16S rDNA sequence analysis and subsequent genetically characterization through comprehensive genomic analysis identified the strain as Pseudomonas pseudoalcaligenes strain YKJ.

Bacterial degradation of bisphenol analogues: an overview

Bisphenol A (BPA) is one of the most produced synthetic monomers in the world and is widespread in the environment. BPA was replaced by bisphenol analogues (BP) because of its adverse effects on life. Bacteria can degrade BPA and other bisphenol analogues (BP), diminishing their environmental concentrations. This study aimed to summarize the knowledge and contribute to future studies. In this review, we surveyed papers on bacterial degradation of twelve different bisphenol analogues published between 1987 and June 2022. A total of 102 original papers from PubMed and Google Scholar were selected for this review. Most of the studies (94.1%, n = 96) on bacterial degradation of bisphenol analogues focused on BPA, and then on bisphenol F (BPF), and bisphenol S (BPS). The number of studies on bacterial degradation of bisphenol analogues increased more than six times from 2000 (n = 2) to 2021 (n = 13). Indigenous microorganisms and the genera Sphingomonas, Sphingobium, and Cupriavidus could degrade several BP. However, few studies focussed on Cupriavidus. The acknowledgement of various aspects of BP bacterial biodegradation is vital for choosing the most suitable microorganisms for the bioremediation of a single BP or a mixture of BP.

Bisphenol A removal and degradation pathways in microorganisms with probiotic properties

Bisphenol-A (BPA) is a constituent of polycarbonate plastics and epoxy resins, widely applied on food packaging materials. As BPA exposure results in health hazards, its efficient removal is of crucial importance. In our study five potentially probiotic microorganisms, namely Lactococcus lactis, Bacillus subtilis, Lactobacillus plantarum, Enterococcus faecalis, and Saccharomyces cerevisiae, were tested for their toxicity tolerance to BPA and their BPA removal ability. Although BPA toxicity, evident on all microorganisms, presented a correlation to both BPA addition time and its concentration, all strains exhibited BPA-removal ability with increased removal rate between 0 and 24 h of incubation. BPA degradation resulted in the formation of two dimer products in cells while the compounds Hydroquinone (HQ), 4-Hydroxyacetophenone (HAP), 4-Hydroxybenzoic acid (HBA) and 4-Isopropenylphenol (PP) were identified in the culture medium. In the proposed BPA degradation pathways BPA adducts formation appears as a common pattern, while BPA decomposition as well as the formation, and the levels of its end products present differences among microorganisms. The BPA degradation ability of the tested beneficial microorganisms demonstrates their potential application in the bioremediation of BPA contaminated foods and feeds and provides a means to suppress the adverse effects of BPA on human and animal health.

Study on bisphenol F, a bisphenol A analogue, at a dairy company: Health hazard and risk assessment

The occurrence of analogues of bisphenol A (BPA), including bisphenol F(BPF) in milk is still not well known. BPF may enter the milk chain at the farm and during milk processing at the dairy company. This study identified the main BPF contamination pathways using a monitoring model based on the identification of the hazard at three stages along the dairy chain: raw milk from the storage tank, pasteurized milk from the storage tank, and cardboard packaged milk. Quantitative analysis was performed by high-performance liquid chromatography with fluorometric detection (HPLC/FD) system. BPF was detected in all analysed stages (from <LOQ to 2.686 μg/L). The structural and toxicological similarity between BPF and BPA suggested considering both bisphenols for a more comprehensive risk evaluation. The daily intake of BPF and of the sum of BPF and BPA, and the worst-case scenario through the consumption of packaged milk were calculated. Exposure levels below the temporary daily intake, fixed for only BPA, were detected in all consumer age classes. Nevertheless, the use of BPA substitutes represents a risk to human health because of their potential synergic effects. The application of a monitoring program at each stage of milk processing at the dairy company may represent a useful strategy to ensure food safety in the milk chain.

Representative Bacillus sp. AM1 from Gut Microbiota Harbor Versatile Molecular Pathways for Bisphenol A Biodegradation

Human gut microbiota harbors numerous microbial species with molecular enzymatic potential that impact on the eubiosis/dysbiosis and health/disease balances. Microbiota species isolation and description of their specific molecular features remain largely unexplored. In the present study, we focused on the cultivation and selection of species able to tolerate or biodegrade the endocrine disruptor bisphenol A (BPA), a xenobiotic extensively found in food plastic containers. Chemical xenobiotic addition methods for the directed isolation, culturing, Whole Genome Sequencing (WGS), phylogenomic identification, and specific gene-encoding searches have been applied to isolate microorganisms, assess their BPA metabolization potential, and describe encoded catabolic pathways. BPA-tolerant strains were isolated from 30% of infant fecal microbial culture libraries analyzed. Most isolated strains were phylogenetically related to the operational taxonomic group Bacillus amyloliquefaciens spp. Importantly, WGS analysis of microbial representative strain, Bacillus sp. AM1 identified the four complete molecular pathways involved on BPA degradation indicating its versatility and high potential to degrade BPA. Pathways for Exopolysaccharide (EPS) and Polyhydroxyalkanates (PHA) biopolymer synthesis were also identified and phenotypically confirmed by transmission electronic microscopy (TEM). These microbial biopolymers could generally contribute to capture and/or deposit xenobiotics.

Bisphenol A removal from a plastic industry wastewater by Dracaena sanderiana endophytic bacteria and Bacillus cereus NI

Understanding the significance of plant-endophytic bacteria for bisphenol A (BPA) removal is of importance for any application of organic pollutant phytoremediation. In this research, Dracaena sanderiana with endophytic Pantoea dispersa showed higher BPA removal than uninoculated plants at 89.54 ± 0.88% and 79.08 ± 1.20%, respectively. Quantitative Real-Time PCR (qPCR) showed that P. dispersa increased from 3.93 × 10⁷ to 8.80 × 10⁷ 16S rRNA gene copy number in root tissues from day 0 to day 5 which indicated that it could assist the plant in removing BPA during the treatment period. pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), conductivity, and salinity were reduced after 5 days of the experimental period. Particularly, BOD significantly decreased due to activities of the plants and microorganisms. Furthermore, an indigenous bacterial strain, Bacillus cereus NI, from the wastewater could remove BPA in high TDS and alkalinity condition of the wastewater. This work suggests that D. sanderiana plants could be used as a tertiary process in a wastewater treatment system and should be combined with its endophytic bacteria. In addition, B. cereus NI could also be applied for BPA removal from wastewaters with high TDS and salinity.

Plant-microbiome assisted and biochar-amended remediation of heavy metals and polyaromatic compounds ─ a microcosmic study

The study has been carried out to develop a plant-microbes assisted remediation technology to accelerate polyaromatic hydrocarbons (PAHs) degradation and heavy metals (HMs) removal in a microcosmic experiment. The quaternary mixture of PAHs (phenanthrene, anthracene, pyrene, and benzo[a] pyrene) and metals (Cr, Ni, and Pb) spiked the soil, constructing a microcosm; the microcosms were bioaugmented with newly developed plant bacterial consortia (Cpm₁ and Cpm₂). The microcosms were amended with biochar (sieved particle size 0.5-2 mm) as redox regulators to reduce oxidative stress of plant-microbe systems. To formulate the two plant-bacterial consortia, plant species were collected and bacteria were isolated from oil spill soil. The bacterial strains used in two formulated consortia includes ─ Cpm₁ (Enterobacter cloacae HS32, Brevibacillus reuszeri HS37, and Stenotrophomonas sp. HS16) and Cpm₂ (Acinetobacter junii HS29, Enterobacter aerogenes HS39 and Enterobacter asburiae HS22). The PAHs degradation and metal removal efficacy of the consortia (Cpm₁ and Cpm₂) were studied after 24 weeks of trial. The physicochemical properties of microcosm's soil (M₂ and M₃) were assessed after experimentation, which resulted in the finding that the soil exhibits dropped in pH from basic to neutral after application of the plant microbe's consortium. The electrical conductivity was lower in M₂ and M₃ soils, with a range between 1.60 and 1.80 mS/cm after the treatment. The Gas Chromatography/Mass Spectrometry (GC/MS) results illustrate how metabolites with the different molecular weight (M.W) were found in M₂ and M₃ soils (184─446), as a result of the plant-microbes mediated rhizodegradation of four spiked PAHs. The metals in microcosm's soil are very low in concentration after 24 weeks of trial when compared to control(M₁). The Cr, Ni and Pb removal percentages were found in 45.79, 42.19 and 44.85 in M₂. However, the removal percentages were found to be 45.41, 41.47 and 44.25 respectively for these same HMs in M₃ soil. Both the consortia that were newly developed showed similar trends of metals removal and PAHs degradation. This study provides a breakthrough in the area of rhizosphere engineering with the goal of maintaining a sustainable application of plant-microbes in ecosystem services.

Cometabolic degradation of bisphenol A by pure culture of Ralstonia eutropha and metabolic pathway analysis

Bisphenol A (BPA) is a toxic compound emitting to the environment mainly by polycarbonate production facilities. In this research, BPA with the initial concentrations in the range of 1-40 mg l^-1 was degraded by Ralstonia eutropha. The bacteria were unable to use BPA as the sole carbon source. Therefore, resting and growing cells of phenol-adapted R. eutropha were used for cometabolic biodegradation of BPA with phenol at the concentration of 100 mg l^-1. The optimum initial concentrations of BPA were 20 mg l^-1 in both approaches of cometabolism. By using resting cells, BPA removal efficiency (RE) reached to 57%, however, RE decreased to 37% by growing cells in the presence of phenol. BPA-degrading activity was inhibited at BPA concentrations >20 mg l^-1. Liquid chromatography-mass spectrometry technique was used to identify some metabolic intermediates generated during BPA degradation process as 1,2-bis(4-hydroxyphenyl)-2-propanol, 4-(2-propanol)-phenol, 4-hydroxyacetophenone, 4-isopropenylphenol, and 4-hydroxybenzoic acid. Finally, metabolic pathways for BPA degradation were proposed in this study.

Dracaena sanderiana endophytic bacteria interactions: Effect of endophyte inoculation on bisphenol A removal

Bisphenol A (BPA) is one of the most abundant endocrine-disrupting compounds which is found in the aquatic environment. However, actual knowledge regarding the effect of plant-bacteria interactions on enhancing BPA removal is still lacking. In the present study, Dracaena sanderiana endophytic bacteria interactions were investigated to evaluate the effect of bacterial inoculation on BPA removal under hydroponic conditions. Two plant growth-promoting (PGP) bacterial strains, Bacillus thuringiensis and Pantoea dispersa, which have high BPA tolerance and can utilize BPA for growth, were used as plant inocula. P. dispersa-inoculated plants showed the highest BPA removal efficiency at 92.32 ± 1.23% compared to other inoculated and non-inoculated plants. This was due to a higher population of the endophytic inoculum within the plant tissues which resulted in maintained levels of indole-3-acetic acid (IAA) for the plant's physiological needs and lower levels of reactive oxygen species (ROS). In contrast, B. thuringiensis-inoculated plants had a lower BPA removal efficiency. However, individual B. thuringiensis possessed a significantly higher BPA removal efficiency compared to P. dispersa. This study provides convincing evidence that not all PGP endophytic bacteria-plant interactions could improve the BPA removal efficiency. Different inocula and inoculation times should be investigated before using plant inoculation to enhance phytoremediation.

Fate of Bisphenol A in Terrestrial and Aquatic Environments

Bisphenol A (2,2-bis[4-hydroxyphenyl]propane, BPA), the monomer used to produce polycarbonate plastic and epoxy resins, is weakly estrogenic and therefore of environmental and human health interest. Due to the high production volumes and disposal of products made from BPA, polycarbonate plastic and epoxy resins, BPA has entered terrestrial and aquatic environments. In the presence of oxygen, diverse taxa of bacteria, fungi, algae and even higher plants metabolize BPA, but anaerobic microbial degradation has not been documented. Recent reports demonstrated that abiotic processes mediate BPA transformation and mineralization in the absence of oxygen, indicating that BPA is susceptible to degradation under anoxic conditions. This review summarizes biological and nonbiological processes that lead to BPA transformation and degradation, and identifies research needs to advance predictive understanding of the longevity of BPA and its transformation products in environmental systems.

An in-depth characterization of the entomopathogenic strain Bacillus pumilus 15.1 reveals that it produces inclusion bodies similar to the parasporal crystals of Bacillus thuringiensis

In the present work, the local isolate Bacillus pumilus 15.1 has been morphologically and biochemically characterized in order to gain a better understanding of this novel entomopathogenic strain active against Ceratitis capitata. This strain could represent an interesting biothechnological tool for the control of this pest. Here, we report on its nutrient preferences, extracellular enzyme production, motility mechanism, biofilm production, antibiotic suceptibility, natural resistance to chemical and physical insults, and morphology of the vegetative cells and spores. The pathogen was found to be β-hemolytic and susceptible to penicillin, ampicillin, chloramphenicol, gentamicin, kanamycin, rifampicin, tetracycline, and streptomycin. We also report a series of biocide, thermal, and UV treatments that reduce the viability of B. pumilus 15.1 by several orders of magnitude. Heat and chemical treatments kill at least 99.9 % of vegetative cells, but spores were much more resistant. Bleach was the only chemical that was able to completely eliminate B. pumilus 15.1 spores. Compared to the B. subtilis 168 spores, B. pumilus 15.1 spores were between 2.67 and 350 times more resistant to UV radiation while the vegetative cells of B. pumilus 15.1 were almost up to 3 orders of magnitude more resistant than the model strain. We performed electron microscopy for morphological characterization, and we observed geometric structures resembling the parasporal crystal inclusions synthesized by Bacillus thuringiensis. Some of the results obtained here such as the parasporal inclusion bodies produced by B. pumilus 15.1 could potentially represent virulence factors of this novel and potentially interesting strain.

Purification and characterization of [Formula: see text]-mannanase from Bacillus pumilus (M27) and its applications in some fruit juices

Thermo alkaline mannanase was purified from the bacteria of Bacillus pumilus (M27) using the techniques of ammonium sulphate precipitation, DEAE-Sephadex ion exchange chromatography and Sephacryl S200 gel filtration chromatography with 111-fold and 36 % yield. It was determined that the enzyme had 2 sub-units including 35 kDa and 55 kDa in gel filtration chromatography and SDS-PAGE electrophoresis systems. The optimum pH and temperature was determined as 8 and 60 °C, respectively. It was also noticed that the enzyme did not lose its activity at a wide interval such as pH 3-11 and at high temperatures such as 90 °C. Additionally, the effects of some metal ions on the mannanase enzyme activity. Moreover, the clarifying efficiency of purified mannanase enzyme with some fruit juices such as orange, apricot, grape and apple was also investigated. Enzymatic treatment was carried out with 1 mL L(-1) of purified mannanase for 1 h at 60 °C. It was determined that the highest pure enzyme was efficient upon clarifying the apple juice at 154 % rate.

Biodegradation of bisphenol A by the newly-isolated Enterobacter gergoviae strain BYK-7 enhanced using genetic manipulation

Endogenous bacterial strains possessing a high bisphenol A (BPA)-tolerance/degradation activity were isolated from different outlets of petrochemical wastewater in Iran using the enrichment cultivation approach.

Concurrent degradation of tetrabromobisphenol A by Ochrobactrum sp. T under aerobic condition and estrogenic transition during these processes

The effect of concurrent degradation of tetrabromobisphenol A (TBBPA) by the strain Ochrobactrum sp. T under aerobic condition was investigated. The results demonstrated that four extra energy source-addition systems still followed pseudo-first order kinetics. The addition of ethanol or glucose could promote the biodegradation ability of Ochrobactrum sp. T to TBBPA, and 90.1 percent and 77.5 percent of TBBPA (5mg L(-1)) could be removed with corresponding TBBPA half-lives of 26 and 36h, respectively, after 96h reaction. Comparatively, the degradation efficiency of the sole TBBPA system was only 72.9 percent under the same condition. In contrast, two other co-substrates 2,4,6-tribromophenol (TBP) and bisphenol A (BPA) showed a negative effect on the TBBPA biodegradation, and the degradation efficiencies of TBBPA were achieved as 44.7 percent and 67.4 percent, respectively. For the TBBPA+TBP system, the competitive inhibition for the TBBPA debromination was less than the inhibition of the toxicity to the bacterium. While for the TBBPA+BPA system, the degradation of TBBPA could be promoted at the beginning of the reaction, and was then inhibited slightly with further prolonging of reaction time. This is probably due to the substrates being oxidized, and BPA can consume partial oxygen and provide the electrons during the concurrent biodegradation process. In addition, although higher estrogenic activity could be detected for the debrominated intermediates in TBBPA co-degradation process than the original TBBPA, the estrogenicity of the whole system still decreased finally after 96h degradation.

Bisphenol A--sources, toxicity and biotransformation

Bisphenol A (BPA) is a chemical compound used in massive amounts in the production of synthetic polymers and thermal paper. In this review, the sources of BPA, which influence its occurrence in the environment and human surrounding will be presented. Data concerning BPA occurrence in food, water and indoor environments as well as its appearance in tissues and body fluids of human body will be shown. The results of in vitro and in vivo studies and the results of epidemiological surveys showing toxic, endocrine, mutagenic and cancerogenic action of BPA will also be discussed. Moreover, data suggesting that exposure of human to BPA may elevate risk of obesity, diabetes and coronary heart diseases will be presented. Finally, biotransformation of BPA in animals, plants and microorganisms (bacteria, fungi, algae), resulting in the formation of various metabolites that exhibit different from BPA toxicity will be described.

Aerobic degradation of bisphenol-A and its derivatives in river sediment

This study investigated the aerobic degradation ofbisphenol-A (BPA) and the derivatives bisphenol-B (BPB), bisphenol-F (BPF), tetrabromobisphenol-A (TBBPA), and tetrachlorobisphenol-A (TCBPA) in river sediment. The degradation rates of BPA and BPF were enhanced by adding brij 30, brij 35, rhamnolipid, surfactin, or crude enzyme; a higher degradation rate was observed with crude enzyme than with the other additives. The degradation rates of BPA and its derivatives (BPAs) in the sediment were BPF > BPA > BPB > TCBPA > TBBPA. Different BPAs affected the changes in the microbial community in the sediment. Sediment fractions with larger particle sizes demonstrated higher degradation rates. Different sediment particle sizes affected the changes in the microbial communities. Pseudomonas sp. may be the dominant bacteria in the process of degradation of BPAs in river sediment.

Bacteria-mediated bisphenol A degradation

Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

Biodegradation and detoxification of bisphenol A with one newly-isolated strain Bacillus sp. GZB: kinetics, mechanism and estrogenic transition

A facultative anaerobic bacterial strain, Bacillus sp. GZB, was isolated and identified to effectively degrade bisphenol A (BPA) under anaerobic and aerobic conditions. Under anaerobic condition, Fe(3+) can be used as an electron acceptor for Bacillus sp. GZB, while 5 mg L(-1) BPA can be fully removed and 51% was mineralized under optimal aerobic conditions. Additionally, seven metabolites were identified by GC-MS, four of which were doubly confirmed by authentic standards (two synthesized) and three of four initial degradation intermediates were also quantified during BPA aerobic degradation. The evolution of 1-(4-hydroxyphenyl)ethanone showed a similar tendency with estrogenic activity changing during BPA biodegradation course, indicating its potential estrogenicity. The estrogenicity temporary increase first and decline ultimately during BPA degradation revealing the GZB can effectively detoxify BPA as well as its estrogenic intermediates. This was the first study to report a facultative anaerobic strain can degrade BPA with or without of oxygen.

A novel thermotolerant and acidotolerant peptide produced by a Bacillus strain newly isolated from a fermented food (kimchi) shows activity against multidrug-resistant bacteria

In an attempt to isolate effective antimicrobial peptides (AMPs) from a microbial source for the treatment of multidrug-resistant (MDR) bacteria, BCP61 was purified from Bacillus sp. CS61 newly isolated from the traditional fermented food kimchi. BCP61 (ca. 1100 Da) was purified to homogeneity using sequential chromatographic steps. It was found to be stable at pH 2.0-10.0 and up to 80 °C. BCP61 displayed antimicrobial activity against MDR bacteria such as meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant S. aureus (VRSA) and vancomycin-resistant enterococci (VRE). Minimal inhibitory concentrations of BCP61 for MRSA, VRSA and VRE were in the range 0.625-20μg/mL. The N-terminal amino acid sequence of BCP61 was A-I-N-X-D-A-A-Y-L, which differed from reported AMPs. The fourth unidentified amino acid was replaced and several peptides were synthesised. Among them, only cysteine replacement displayed antimicrobial activity. BCP61 from a food-borne strain may be useful in therapeutic applications.

Isolation and characterization of novel bisphenol-A--degrading bacteria from soils

One hundred and seven soil samples were collected from various places in Japan, and their bisphenol-A (BPA, 2,2-bis(4-Hydroxyphenyl) propane) degradative capacities were evaluated. Eighty-five soil samples possessed BPA degradative capacities, and 26 bacterial strains could be isolated as BPA-degrading bacterium. Sequence analysis of their 16S rRNA genes indicated that 22 isolates belonged to proteobacteria groups, and three of four Gram-positive bacterial strains, YA27, NO13, and NO15, were classified as Bacilli. All isolates except strain YA27 completely degraded 115 microg/mL BPA in L medium but strain YA27 degraded only 50 microg/mL BPA. Strain YA27 and three Sphingomonas sp. strains could also grow in basal salt media containing BPA as a sole carbon source (BSMB medium). In HPLC analyses, some isolates, including the three Sphingomonas strains, produced some BPA metabolites in their cultures although the others, including strain YA27, produced no detectable metabolite. Furthermore, the Pseudomonas strains SU1 and SU4 produced some BPA metabolites that were different from the metabolites detected in the degradation of BPA by the S. bisphenolicum strain AO1. These results suggested that all isolates could be applicable to the bioremediation of BPA-polluted soil and water. Furthermore, we suggest that Bacillus sp. YA27 and Pseudomonas SU1 and SU4 may exhibit novel BPA metabolism pathways that are distinct from that of S. bisphenolicum AO1.

Bioremediation of Bisphenol A and Benzophenone by Glycosylation with Immobilized Marine Microalga Pavlova sp

Cultured cells of Pavlova sp. glycosylated bisphenol A to its mono-glucoside, 2-(4-beta-D-glucopyranosyloxyphenyl)-2-hydroxyphenylpropane (9%). Use of immobilized Pavlova cells in sodium alginate gel improved yield of the product (17%). On the other hand, Pavlova cell cultures converted benzophenone into diphenylmethanol (49%) and diphenylmethyl beta-D-glucopyranoside (6%). Incubation of benzophenone with immobilized Pavlova cells gave products in higher yields; the yields of diphenylmethanol and diphenylmethyl beta-D-glucopyranoside were 85 and 15%, respectively.