Bacterial Degradation Research Articles

Highly dispersed Pd icosahedra and Ag nanocubes on ultrathin g-C3N4 nanosheet for boosting photocatalytic bacterial inactivation and organic pollutants degradation

Engineering surface facet of metallic nanoparticles that decorated on certain substants is an intriguing strategy to modulate photocatalytic capacity. Herein, a novel photocatalyst by doping g-C3N4 nanosheet with Pd icosahedra with {111} facets and Ag nanocubes with {100} facets were firstly synthesized through facile wet-chemical route. The successfully constructed g-C3N4/Pd/Ag composites were employed as a visible-light-driven dual-functional photocatalyst for bacterial inactivation and organic contaminant degradation. Result suggested that 1 × 108 CFU/mL E. coli strains can be totally inactivated by g-C3N4/Pd/Ag within 60 min, outperformed that of {100} faceted enclosed Pd nanocubes functioned g-C3N4/Ag. Also, the optimized g-C3N4/Pd/Ag exhibited ideal photocatalytic performance toward tetracycline and methylene blue degradation. The rate constant was found to be 8.74 × 10−3 and 7.08 × 10−3 min−1, respectively, which was higher than those of bare g-C3N4 and g-C3N4/Pd. Quenching experiment and electron paramagnetic resonance analysis suggested that hole (h+), electron (e−), and superoxide radical (O2−) exerted a key role in the improved capacity. Furthermore, the more positive Fermi level of Pd icosahedra and Ag nanocubes relative to that of g-C3N4 also contributed to the enhanced photocatalytic performance. Collectively, our work can provide in-depth insight into fabricate novel facet-engineering photocatalyst for environmental applications.

Identification of kinase modulators as host-directed therapeutics against intracellular methicillin-resistant Staphylococcus aureus.

The increasing prevalence of antimicrobial-resistant Staphylococcus aureus strains, especially methicillin-resistant S. aureus (MRSA), poses a threat to successful antibiotic treatment. Unsuccessful attempts to develop a vaccine and rising resistance to last-resort antibiotics urge the need for alternative treatments. Host-directed therapy (HDT) targeting critical intracellular stages of S. aureus emerges as a promising alternative, potentially acting synergistically with antibiotics and reducing the risk of de novo drug resistance. We assessed 201 ATP-competitive kinase inhibitors from Published Kinase Inhibitor Sets (PKIS1 and PKIS2) against intracellular MRSA. Seventeen hit compounds were identified, of which the two most effective and well-tolerated hit compounds (i.e., GW633459A and GW296115X) were selected for further analysis. The compounds did not affect planktonic bacterial cultures, while they were active in a range of human cell lines of cervical, skin, lung, breast and monocyte origin, confirming their host-directed mechanisms. GW633459A, structurally related to lapatinib, exhibited an HDT effect on intracellular MRSA independently of its known human epidermal growth factor receptor (EGFR)/(HER) kinase family targets. GW296115X activated adenosine monophosphate-activated protein kinase (AMPK), thereby enhancing bacterial degradation via autophagy. Finally, GW296115X not only reduced MRSA growth in human cells but also improved the survival rates of MRSA-infected zebrafish embryos, highlighting its potential as HDT.

Reducing Detergent from River Using Bio Augmentation

This project is based on reducing detergent from river which is been released in any form it may be from washing clothes, soaps, shampoos, etc. we cannot separate as it mixed in water. So, detergent degrading bacteria should be used. Bacterial species that can degrade detergent easily are pseudomonas, bacillus subtilis, Staphylococcus, coliform bacteria i.e E.coli. Degrading efficiency depends on strain that is used which can be determined by measuring optical density or doing titration. Keywords: Detergent, Optical density, bacterial degradation.

Integrated Electrochemical Oxidation and Biodegradation for Remediation of a Neonicotinoid Insecticide Pollutant.

A novel integrated electrochemical oxidation (EO) and bacterial degradation (BD) technique was employed for the remediation of the chloropyridinyl and chlorothiazolyl classes of neonicotinoid (NEO) insecticides in the environment. Imidacloprid (IM), clothianidin (CL), acetamiprid (AC), and thiamethoxam (TH) were chosen as the target NEOs. Pseudomonas oleovorans SA2, identified through 16S rRNA gene analysis, exhibited the potential for BD. In EO, for the selected NEOs, the total percentage of chemical oxygen demand (COD) was noted in a range of 58-69%, respectively. Subsequently, in the biodegradation of EO-treated NEOs (BEO) phase, a higher percentage (80%) of total organic carbon removal was achieved. The optimum concentration of NEOs was found to be 200 ppm (62%) for EO, while for BEO, the COD efficiency was increased up to 79%. Fourier-transform infrared spectroscopy confirms that the heterocyclic group and aromatic ring were degraded in the EO and further utilized by SA2. Gas chromatography-mass spectroscopy indicated up to 96% degradation of IM and other NEOs in BD (BEO) compared to that of EO (73%). New intermediate molecules such as silanediamine, 1,1-dimethyl-n,n'-diphenyl produced during the EO process served as carbon sources for bacterial growth and further mineralized. As a result, BEO enhanced the removal of NEOs with a higher efficiency of COD and a lower consumption of energy. The removal efficiency of the NEOs by the integrated approach was achieved in the order of AC > CL > IM > TH. This synergistic EO and BD approach holds promise for the efficient detoxification of NEOs from polluted environments.

Microbiological evaluation of bovine carcasses decontaminated with lactic acid solution

Bovine meat is a nutritious food product that is highly susceptible to bacterial degradation. Organic acid spray washing can be used to reduce microbial populations in carcasses. This study aimed to examine the efficacy of lactic acid in reducing total coliforms and Escherichia coli and assess the effects of different lactic acid concentrations on meat. For this, bovine carcasses were classified into cleanliness categories and subjected to swab sampling before and after manual and automated washing with lactic acid solution at different concentrations (0, 0.5%, 1%, 2%, 3%, and 4%). Colorimetric analysis and lactic acid quantification of carcasses were performed at 0 and 24 h post mortem. The experiment followed a factorial design. Lactic acid inhibited microbial growth, particularly automated application of 3% lactic acid. Although minor changes in color were observed, lactic acid washing was beneficial from a microbial standpoint, effectively decontaminating bovine carcasses and leaving only minimum amounts of residual acid in meat.

Seed-borne bacterial synthetic community resists seed pathogenic fungi and promotes plant growth.

In this study, the control effects of synthetic microbial communities composed of peanut seed bacteria against seed aflatoxin contamination caused by Aspergillus flavus and root rot by Fusarium oxysporum were evaluated. Potentially conserved microbial synthetic communities (C), growth-promoting synthetic communities (S), and combined synthetic communities (CS) of peanut seeds were constructed after 16S rRNA Illumina sequencing, strain isolation, and measurement of plant growth promotion indicators. Three synthetic communities showed resistance to root rot and CS had the best effect after inoculating into peanut seedlings. This was achieved by increased defense enzyme activity and activated salicylic acid (SA)-related, systematically induced resistance in peanuts. In addition, CS also inhibited the reproduction of A. flavus on peanut seeds and the production of aflatoxin. These effects are related to bacterial degradation of toxins and destruction of mycelia. Inoculation with a synthetic community composed of seed bacteria can help host peanuts resist the invasion of seeds by A. flavus and seedlings by F. oxysporum and promote the growth of peanut seedlings.

Choline degradation in Paracoccus denitrificans: identification of sources of formaldehyde.

Paracoccus denitrificans is a facultative methylotroph that can grow on methanol and methylamine as sole sources of carbon and energy. Both are oxidized to formaldehyde and then to formate, so growth on C1 substrates induces the expression of genes encoding enzymes required for the oxidation of formaldehyde and formate. This induction involves a histidine kinase response regulator pair (FlhSR) that is likely triggered by formaldehyde. Catabolism of some complex organic substrates (e.g., choline and L-proline betaine) also generates formaldehyde. Thus, flhS and flhR mutants that fail to induce expression of the formaldehyde catabolic enzymes cannot grow on methanol, methylamine, and choline. Choline is oxidized to glycine via glycine betaine, dimethylglycine, and sarcosine. By exploring flhSR growth phenotypes and the activities of a promoter and enzyme known to be upregulated by formaldehyde, we identify the oxidative demethylations of glycine betaine, dimethylglycine, and sarcosine as sources of formaldehyde. Growth on glycine betaine, dimethylglycine, and sarcosine is accompanied by the production of up to three, two, and one equivalents of formaldehyde, respectively. Genetic evidence implicates two orthologous monooxygenases in the oxidation of glycine betaine. Interestingly, one of these appears to be a bifunctional enzyme that also oxidizes L-proline betaine (stachydrine). We present preliminary evidence to suggest that growth on L-proline betaine induces expression of a formaldehyde dehydrogenase distinct from the enzyme induced during growth on other formaldehyde-generating substrates.IMPORTANCEThe bacterial degradation of one-carbon compounds (methanol and methylamine) and some complex multi-carbon compounds (e.g., choline) generates formaldehyde. Formaldehyde is toxic and must be removed, which can be done by oxidation to formate and then to carbon dioxide. These oxidations provide a source of energy; in some species, the CO2 thus generated can be assimilated into biomass. Using the Gram-negative bacterium Paracoccus denitrificans as the experimental model, we infer that oxidation of choline to glycine generates up to three equivalents of formaldehyde, and we identify the three steps in the catabolic pathway that are responsible. Our work sheds further light on metabolic pathways that are likely important in a variety of environmental contexts.

Immiscible Rayleigh–Taylor turbulence: Implications for bacterial degradation in oil spills

An unstable density stratification between two fluids mixes spontaneously under the effect of gravity, a phenomenon known as Rayleigh-Taylor (RT) turbulence. If the two fluids are immiscible, for example, oil and water, surface tension prevents intermixing at the molecular level. However, turbulence fragments one fluid into the other, generating an emulsion in which the typical droplet size decreases over time as a result of the competition between the rising kinetic energy and the surface energy density. Even though the first phenomenological theory describing this emulsification process was derived many years ago, it has remained elusive to experimental verification, hampering our ability to predict the fate of oil in applications such as deep-water spills. Here, we provide the first experimental and numerical verification of the immiscible RT turbulence theory, unveiling a unique turbulent state that originates at the oil-water interface due to the interaction of multiple capillary waves. We show that a single, non-dimensional, and time-independent parameter controls the range of validity of the theory. Our findings have wide-ranging implications for the understanding of the mixing of immiscible fluids. This includes in particular oil spills, where our work enables the prediction of the oil-water interface dynamics that ultimately determine the rate of oil biodegradation by marine bacteria.

A multifunctional flavoprotein monooxygenase HspB for hydroxylation and C-C cleavage of 6-hydroxy-3-succinoyl-pyridine.

Flavoprotein monooxygenases catalyze reactions, including hydroxylation and epoxidation, involved in the catabolism, detoxification, and biosynthesis of natural substrates and industrial contaminants. Among them, the 6-hydroxy-3-succinoyl-pyridine (HSP) monooxygenase (HspB) from Pseudomonas putida S16 facilitates the hydroxylation and C-C bond cleavage of the pyridine ring in nicotine. However, the mechanism for biodegradation remains elusive. Here, we refined the crystal structure of HspB and elucidated the detailed mechanism behind the oxidative hydroxylation and C-C cleavage processes. Leveraging structural information about domains for binding the cofactor flavin adenine dinucleotide (FAD) and HSP substrate, we used molecular dynamics simulations and quantum/molecular mechanics calculations to demonstrate that the transfer of an oxygen atom from the reactive FAD peroxide species (C4a-hydroperoxyflavin) to the C3 atom in the HSP substrate constitutes a rate-limiting step, with a calculated reaction barrier of about 20 kcal/mol. Subsequently, the hydrogen atom was rebounded to the FAD cofactor, forming C4a-hydroxyflavin. The residue Cys218 then catalyzed the subsequent hydrolytic process of C-C cleavage. Our findings contribute to a deeper understanding of the versatile functions of flavoproteins in the natural transformation of pyridine and HspB in nicotine degradation.IMPORTANCEPseudomonas putida S16 plays a pivotal role in degrading nicotine, a toxic pyridine derivative that poses significant environmental challenges. This study highlights a key enzyme, HspB (6-hydroxy-3-succinoyl-pyridine monooxygenase), in breaking down nicotine through the pyrrolidine pathway. Utilizing dioxygen and a flavin adenine dinucleotide cofactor, HspB hydroxylates and cleaves the substrate's side chain. Structural analysis of the refined HspB crystal structure, combined with state-of-the-art computations, reveals its distinctive mechanism. The crucial function of Cys218 was never discovered in its homologous enzymes. Our findings not only deepen our understanding of bacterial nicotine degradation but also open avenues for applications in both environmental cleanup and pharmaceutical development.

Unravelling the role of coumarin on anaerobic digestion of waste activated sludge: Determination of operational dynamics and microbial community structure

Anaerobic digestion, as an effective method for sludge treatment, still has excellent potential for development in energy recovery. Therefore, this study proposed a method to increase methane production by adding coumarin (a green antibacterial agent). The results indicated that coumarin can significantly improve the methane production performance of sludge, but high coumarin concentrations delay methane production. Methane generation through the acetoclastic pathway is inhibited at high concentrations of coumarin and can be restored after bacterial adaptation or degradation of coumarin. Mechanism exploration revealed that coumarin enhanced the destruction of EPS and poorly tolerant bacterial cell membranes, thereby benefiting the solubilization of sludge. It was also found that coumarin promotes sludge hydrolysis, acidification, and methane production stages. Microbial analysis revealed that the abundance of functional microorganisms in the coumarin reactor was more advantageous to methane production. These findings are expected to provide a reference for enhancing the methane production performance of sludge.

Impact of Reactive Sulfur Species on Entamoeba histolytica: Modulating Viability, Motility, and Biofilm Degradation Capacity.

Reactive sulfur species (RSS) like hydrogen sulfide (H2S) and cysteine persulfide (Cys-SSH) emerged as key signaling molecules with diverse physiological roles in the body, depending on their concentration and the cellular environment. While it is known that H2S and Cys-SSH are produced by both colonocytes and by the gut microbiota through sulfur metabolism, it remains unknown how these RSS affect amebiasis caused by Entamoeba histolytica, a parasitic protozoan that can be present in the human gastrointestinal tract. This study investigates H2S and Cys-SSH's impact on E. histolytica physiology and explores potential therapeutic implications. Exposing trophozoites to the H2S donor, sodium sulfide (Na2S), or to Cys-SSH led to rapid cytotoxicity. A proteomic analysis of Cys-SSH-challenged trophozoites resulted in the identification of >500 S-sulfurated proteins, which are involved in diverse cellular processes. Functional assessments revealed inhibited protein synthesis, altered cytoskeletal dynamics, and reduced motility in trophozoites treated with Cys-SSH. Notably, cysteine proteases (CPs) were significantly inhibited by S-sulfuration, affecting their bacterial biofilm degradation capacity. Immunofluorescence microscopy confirmed alterations in actin dynamics, corroborating the proteomic findings. Thus, our study reveals how RSS perturbs critical cellular functions in E. histolytica, potentially influencing its pathogenicity and interactions within the gut microbiota. Understanding these molecular mechanisms offers novel insights into amebiasis pathogenesis and unveils potential therapeutic avenues targeting RSS-mediated modifications in parasitic infections.

A189 INVESTIGATING THE ROLE OF BACTERIAL HISTAMINE METABOLISM IN VISCERAL HYPERALGESIA

Abstract Background Intestinal microbiota have been implicated in the expression of irritable bowel syndrome (IBS) as patients present with altered gut microbial profiles and microbial metabolic activity. We have previously identified bacterial histamine to strongly influence mast cell accumulation through only IBS activation of the H4 receptor, leading to visceral hyperalgesia in a subset of patients with IBS. We hypothesize that a subset of IBS patients with high histamine-producing microbiota exhibit an aberrant histamine metabolism. Investigating the microbiota-driven pathways involved in histamine metabolism is key to understanding abdominal pain pathophysiology in IBS patients. Aims 1. To study whether variations of histamine levels are due to bacterial metabolism using in vitro and in vivo approaches. 2. To identify the prevalence of high histamine-producing and histamine-degrading bacteria in a clinical cohort via in silico analyses. Methods Using in vitro approaches, stool samples from healthy control (HC) donors and IBS patients were inoculated in minimal media in aerobic/anaerobic conditions, with/without excess histidine or added histamine. Bacterial histamine production and degradation were assessed in culture supernatants by ELISA. After identification through Sanger sequencing, individual colony capacity to degrade and produce histamine was assessed. Host and microbial contributions to histamine metabolism will be identified through analyses of germ-free mice colonized with IBS and HC stool samples. Results IBS patients (n=23) tested were found to consistently produce higher levels of histamine compared to HC (n=3). Among the tested isolated colonies from IBS patients (n=179) 61% produced histamine compared to 33% of HC (n=54), and 20% degraded histamine compared to 11% of HC. Of these colonies, 13% of only IBS isolates demonstrated the capacity to both degrade and produce histamine. Facultative anaerobes were found to possess both higher production and degradation capacity. Both pH and histamine concentration determine bacterial ability to produce or degrade histamine. Conclusions Based on these findings, both healthy and IBS individuals exhibit varying levels of histamine production/degradation, most prominently through facultative anaerobes. The intestinal environment and bacterial community composition are major regulators of bacterial histamine metabolism. The observed in vitro capacity to produce/degrade histamine, and its biological implications, will be confirmed with gnotobiotic humanized mice, ultimately aiding in designing microbiota-directed therapies for the management of visceral hypersensitivity. Funding Agencies CIHRFarncombe Innovation Fund

Biodegradation of 17β‐estradiol by drug‐resistant Stenotrophomonas maltophilia MN08 and Pseudomonas aeruginosa KL10 isolated from the sediment sample

Abstract17 β‐Estradiol is produced by animals, and humans and excreted through excreta, and has endocrine‐disrupting activity. Bacterial degradation is one of the suitable methods used for the removal of 17 β‐estradiol (E2) from the natural environment. In this study, E2‐degrading bacteria were screened from the enriched sediment sample from the wastewater environment. Two bacterial strains of E2‐degrading bacteria (Stenotrophomonas maltophilia MN08 and Pseudomonas aeruginosa KL10) were determined and >70% of E2‐degradation was achieved. The strain MN08 could rapidly remove approximately 86.5% ± 1.3% of E2 within 7 days of treatment. In addition, the strain KL10 removed 79.5% ± 1% of E2 within the same period. Optimized culture temperature and pH of the medium could improve E2‐degradation. The results demonstrated that the strain MN08 exhibited maximum E2‐degradation activity at 35°C, and pH 8.0. The optimal pH for strain KL10 to degrade E2 ranged from 7.0 to 9.0. The E2‐degradation level for the mixture culture systems can exhibit synergistic E2‐degradation activity. The degradation of the MN08 and KL10 individual strains was 87.3% ± 1.2% and 81.4% ± 1.5%, respectively. The E2‐degradation potential for the mixed culture system was 91.3% ± 2.9% under optimized conditions in which 100 mg/L of E2 served as the sole source of carbon and energy. The present finding demonstrates that the co‐culture of S. maltophilia MN08 and P. aeruginosa KL10 may provide a promising bio‐treatment strategy for the removal of steroids from wastewater.

Pretreatment by a novel photo-electro reactor to control organic and biofouling during reverse osmosis filtration of reclaimed water

This study reports the performance of a novel photo-electro filtration (PEF) reactor consisting of an IrO2/RuO2 coated anodic filter and UV lamp to pretreat biologically treated wastewater effluent prior to reverse osmosis (RO) filtration. Synthetic model solutions and biologically treated wastewater effluent were used for systematic evaluation of the PEF reactor performance in terms of organic degradation, bacterial inactivation, biofilm formation reduction, and ultimately RO fouling mitigation. Experiments with model solutions containing proteins (Bovine Serum Albumin) and bacteria (Pseudomonas aeruginosa) show that UV irradiation and electrochemical treatment with increasing voltage input resulted in superior bacterial inactivation, biofilm formation reduction, and effective organic degradation. When the PEF reactor was used to pretreat biologically treated wastewater effluent, electrochemical treatment at 3 V alone and the combination of electrochemical treatment at 3 V and UV could achieve near complete bacterial inactivation and good fouling reduction during subsequent RO operation. However, the combination of electrochemical treatment at 3 V and UV was superior over electrochemical treatment at 3 V alone in several aspects including fouling reduction and reduced risk of membrane degradation due to chlorine residue. The underlying mechanisms responsible for effective PEF pretreatment performance were elucidated by monitoring the fate of free chlorine, hydroxyl radicals (indirectly monitored by measuring concentration of the quenching chemical N-n-dimethyl-p-nitrosoaniline), H2O2, quorum sensing signal molecules, and organic fractions during UV irradiation and electrochemical treatment. Effective bio and organic fouling mitigation by PEF pretreatment was attributed to the enhanced bacterial inactivation and degradation of organic compounds (primarily protein-like and humic-like substances) by hydroxyl radicals (∙OH) produced from photo-electrochemical treatment.

Bacteria use a catabolic patchwork pathway of apparently recent origin for degradation of the synthetic buffer compound TRIS.

The synthetic buffer compound TRIS (2-amino-2-(hydroxymethyl)propane-1,3-diol) is used in countless applications, and no detailed information on its degradation has been published so far. Herein, we describe the discovery of a complete bacterial degradation pathway for TRIS. By serendipity, a Pseudomonas strain was isolated from sewage sludge that was able to grow with TRIS as only carbon and nitrogen source. Genome and transcriptome analyses revealed two adjacent gene clusters embedded in a mobile genetic element on a conjugative plasmid to be involved in TRIS degradation. Heterologous gene expression revealed cluster I to encode a TRIS uptake protein, a TRIS alcohol dehydrogenase, and a TRIS aldehyde dehydrogenase, catalyzing the oxidation of TRIS into 2-hydroxymethylserine. Gene cluster II encodes a methylserine hydroxymethyltransferase (mSHMT) and a d-serine dehydratase that plausibly catalyze the conversion of 2-hydroxymethylserine into pyruvate. Conjugational plasmid transfer into Pseudomonas putida KT2440 enabled this strain to grow with TRIS and with 2-hydromethylserine, demonstrating that the complete TRIS degradation pathway can be transmitted by horizontal gene transfer. Subsequent enrichments from wastewater purification systems led to the isolation of further TRIS-degrading bacteria from the Pseudomonas and Shinella genera carrying highly similar TRIS degradation gene clusters. Our data indicate that TRIS degradation evolved recently via gene recruitment and enzyme adaptation from multiple independent metabolic pathways, and database searches suggest that the TRIS degradation pathway is now globally distributed. Overall, our study illustrates how engineered environments can enhance the emergence of new microbial metabolic pathways in short evolutionary time scales.

Bacterial degradation of phenol: a review of the current state of knowledge

Phenol is a toxic and recalcitrant contaminant widely used in various industries, including petrochemical, pharmaceutical, and agrochemical industries. Bacterial degradation of phenol is a promising method for treating phenol-contaminated wastewater. The biodegradation of phenol by bacteria can effectively remove it from the environment, making it a valuable alternative to traditional chemical treatment methods. This review summarizes the current knowledge on the bacterial biodegradation of phenol, including those in the petrochemical, pharmaceutical, and agrochemical sectors, the metabolic pathways involved in phenol degradation, and the factors that influence the efficiency of phenol biodegradation. This paper also discusses the challenges and limitations of using bacteria for the biodegradation of phenol, including the need for further research to improve the efficiency and sustainability of the process. The outcome of this review demonstrates that bacterial biodegradation is a promising and effective method for treating phenol-contaminated wastewater and provides a foundation for future research to improve the efficiency and continuous use of this process.

Potential of Bacterial Isolates and Consortiums for Degrading Linear Alkylbenzenesulfonate, Ammonia, and Phosphate in the Kaliotic River

River pollution by various organic and inorganic compounds such as linear alkylbenzenesulfonate (LAS), ammonia, and phosphate is a serious environmental problem in the Kaliotic River. This research investigates the potential of bacterial isolates and consortia for degrading these pollutants. We conducted a field survey and collected water samples from the Kaliotic River and isolated bacteria from these water samples. Next, we tested the ability of single isolates and bacterial consortia to degrade LAS, ammonia, and phosphate in vitro. The results showed that various bacterial isolates isolated from the Kaliotic River showed varying abilities to degrade LAS, ammonia, and phosphate. Some single isolates could degrade LAS to a significant extent, whereas other isolates showed higher activity in reducing ammonia and phosphate concentrations in the medium. The bacterial consortium consisting of several isolates also showed promising potential for degrading these three pollutants. Further analysis using molecular techniques such as 16S rRNA DNA sequencing shows the genetic diversity of bacteria involved in pollutant degradation. This study also highlights the importance of environmental factors such as temperature, pH, and nutrient availability in influencing bacterial degradation activity. These findings indicate that bacterial isolates and consortia have great potential for degrading LAS, ammonia, and phosphate in the Kaliotic River. This research provides new insights into the potential application of microbes in environmental remediation efforts in polluted rivers. By better understanding the mechanisms of degradation and the factors that influence bacterial activity, it is hoped that more effective and sustainable strategies can be developed to rid rivers of these dangerous pollutants.

Protein degradation in bacteria: focus on the ClpP protease

Proteins in the cells are born (synthesized), work, and die (decomposed). In the life of a protein, its birth is obviously important, but how it dies is equally important in living organisms. Proteases secreted into the outside of cells are used to decompose the external proteins and the degradation products are taken as the nutrients. On the other hand, there are also proteases that decompose unnecessary or harmful proteins which are generated in the cells. In eukaryotes, a large enzyme complex called the proteasome is primarily responsible for degradation of such proteins. Bacteria, which are prokaryotes, have a similar system as the proteasome. We would like to explain the bacterial degradation system of proteins or the death of proteins, which is performed by ATP-dependent protease Clp, with a particular focus on the ClpXP complex, and with an aspect as a target for antibiotics against bacteria.

Microbe-pesticide interactions: Soil enzyme analysis and bacterial degradation of chlorpyrifos

With the objective of understanding microbe—pesticide interactions in soil, the effect of pesticides alone and in combination on the activities of amylase, cellulase, and invertase was assessed in black, and red soils collected from the groundnut (Arachis hypogaea L.) cultivated fields of Andhra Pradesh, India. In addition, the potential bacteria that can break down chlorpyrifos was identified using biochemical assays and a partial 16S rRNA gene sequence analysis. Soil enzymes were analyzed using standard procedures described elsewhere. The activities of amylase, cellulase, and invertase were solely dependent on the dose of pesticides used in the current study. Enzyme activities were significantly increased at the level of 2.5 or 5.0 kg ha–1, whereas increases in the concentration of pesticides at 7.5–10 kg ha−1 were lethal to the enzyme activities in both soils at 10-day incubation. The effective combination for the increase in the activities of amylase, cellulase, and invertase were monocrotophos + mancozeb. Mineral salts medium with 50 ppm chlorpyrifos as a carbon source had the greatest growth of the bacteria (i.e. Pseudomonas citronellolis strain CF3) at 14th h of incubation with OD value of 0.24 at 660 nm, and the same strain could eliminate 75% of the chlorpyrifos within 24 h from the medium. Based on the present study it was concluded that insecticides used alone or in combination with fungicides at specific doses (2.5 or 5.0 kg ha−1) improved the amylase, cellulase, and invertase activities, which are involved in the carbon cycle in soils. Pseudomonas citronellolis strain CF3 is a potential bacterium in the remediation of chlorpyrifos-contaminated sites.

Microbial Degradation Of Calcium Oxalate And Its Potential Application

Calcium oxalate is a naturally occurring compound found in various plants and minerals, and its accumulation in the kidney leads to the formation of kidney stones in humans. One of the main causes of kidney stone formation is a decrease in the number of intestinal microbiota which are capable of degrading calcium oxalate. This study focuses on bacterial degradation of calcium oxalate accumulated in humans. Searching for Calcium oxalate degrading strain with high degrading activity has become one of the priorities from the context of research. The study aimed to isolate and characterize microorganisms which are capable of degrading calcium oxalate. Calcium oxalate degrading microorganisms were isolated from faecal samples by using MRS-calcium oxalate medium. Calcium oxalate degrading bacteria were identified on the basis of colour reduction on calcium oxalate medium plate after the incubation period. The morphological and biochemical characterization of isolates were studied. Quantitative determination of degradation was performed by using an indole assay. The activity of isolates was observed by the degradation of kidney stones. Isolates showed better results for degradation of kidney stones after 2 weeks of the incubation period.