The Capability of Utilizing Abiotic Enantiomers of Amino Acids by Halomonas sp. LMO_D1 Derived From the Mariana Trench

D-amino acids (D-AAs) have been produced both in organisms and in environments via biotic or abiotic processes. However, the existence of these organic materials and associated microbial degradation activity has not been previously investigated in subduction zones where tectonic activities result in the release of hydrothermal organic matter. Here, we isolated the bacterium Halomonas sp. LMO_D1 from a sample obtained from the Mariana trench, and we determined that this isolate utilized 13 different D-AAs (D-Ala, D-Glu, D-Asp, D-Ser, D-Leu, D-Val, D-Tyr, D-Gln, D-Asn, D-Pro, D-Arg, D-Phe, and D-Ile) in the laboratory and could grow on D-AAs under high hydrostatic pressure (HHP). Moreover, the metabolism of L-AAs was more severely impaired under HHP conditions compared with that of their enantiomers. The essential function gene (Chr_2344) required for D-AA catabolism in strain LMO_D1 was identified and confirmed according to the fosmid library method used on the D-AAs plate. The encoded enzyme of this gene (DAADH_2344) was identified as D-amino acid dehydrogenase (DAADH), and this gene product supports the catabolism of a broad range of D-AAs. The ubiquitous distribution of DAADHs within the Mariana Trench sediments suggests that microorganisms that utilize D-AAs are common within these sediments. Our findings provide novel insights into the microbial potential for utilizing abiotic enantiomers of amino acids within the subduction zone of the Mariana trench under HHP, and our results provide an instructive significance for understanding these abiotic enantiomers and allow for insights regarding how organisms within extraterrestrial HHP environments can potentially cope with toxic D-AAs.

EVALUATION OF ANTI-MICROBIAL POTENTIAL OF STRUCTURALLY MODIFIED DERIVATIVES OF LEAD COMPOUND BERBERINE ISOLATED FROM ROOTS OF BERBERIS ARISTATA

The alkaloid berberine, the chief constituent of Berberis aristata, has been reported to have antimicrobial activity associated with it. Structural changes can be made to this lead compound to try to improve its effi cacy in terms of antimicrobial activity. In the present study, attempts have been made to evaluate anti-microbial potential of structurally modifi ed derivatives of berberine. The derivatives so synthesized were characterized on the basis of spectral techniques like 1H,13C NMR, UV, IR and MASS and by comparison with standard berberine. Structure-activity relationship studies revealed that methoxyl group is pharmacophore of berberine and is thus needed to be retained in the skeleton. Further incorporation of the electron-withdrawing group has pronounced effect on the antimicrobial activity. Further attempts could be made to extend the series with the incorporation of such electron-withdrawing groups to get potent antimicrobial agents.

Integrating Decomposers, Methane-Cycling Microbes and Ecosystem Carbon Fluxes Along a Peatland Successional Gradient in a Land Uplift Region

Peatlands are carbon dioxide (CO2) sinks that, in parallel, release methane (CH4). The peatland carbon (C) balance depends on the interplay of decomposer and CH4-cycling microbes, vegetation, and environmental conditions. These interactions are susceptible to the changes that occur along a successional gradient from vascular plant-dominated systems to Sphagnum moss-dominated systems. Changes similar to this succession are predicted to occur from climate change. Here, we investigated how microbial and plant communities are interlinked with each other and with ecosystem C cycling along a successional gradient on a boreal land uplift coast. The gradient ranged from shoreline to meadows and fens, and further to bogs. Potential microbial activity (aerobic CO2 production; CH4 production and oxidation) and biomass were greatest in the early successional meadows, although their communities of aerobic decomposers (fungi, actinobacteria), methanogens, and methanotrophs did not differ from the older fens. Instead, the functional microbial communities shifted at the fen–bog transition concurrent with a sudden decrease in C fluxes. The successional patterns of decomposer versus CH4-cycling communities diverged at the bog stage, indicating strong but distinct microbial responses to Sphagnum dominance and acidity. We highlight young meadows as dynamic sites with the greatest microbial potential for C release. These hot spots of C turnover with dense sedge cover may represent a sensitive bottleneck in succession, which is necessary for eventual long-term peat accumulation. The distinctive microbes in bogs could serve as indicators of the C sink function in restoration measures that aim to stabilize the C in the peat.

Distribution of a Sulfolane-Metabolizing Rhodoferax sp. Throughout a Contaminated Subarctic Aquifer and Two Groundwater Treatment Systems

An extensive plume of the emerging contaminant sulfolane has been found emanating from a refinery in Interior Alaska, raising questions about the microbial potential for natural attenuation and bioremediation in this subarctic aquifer. Previously, an aerobic sulfolane-assimilating Rhodoferax sp. was identified from the aquifer using stable isotope probing. Here, we assessed the distribution of known sulfolane-assimilating bacteria throughout the contaminated subarctic aquifer using 16S-rRNA-amplicon analyses of ~100 samples collected from groundwater monitoring wells and two groundwater treatment systems. One treatment system was an in situ air sparging system where air was injected directly into the aquifer. The other was an ex situ granular activated carbon (GAC) filtration system for the treatment of private well water. We found that the sulfolane-assimilating Rhodoferax sp. was present throughout the aquifer but was significantly more abundant in groundwater associated with the air sparge system. The reduction of sulfolane concentrations combined with the apparent enrichment of sulfolane degraders in the air sparging zone suggests that the addition of oxygen facilitated sulfolane biodegradation. To investigate other environmental controls on Rhodoferax populations, we also examined correlations between groundwater geochemical parameters and the relative abundance of the Rhodoferax sp. and found only manganese to be significantly positively correlated. The sulfolane-assimilating Rhodoferax sp. was not a major component of the GAC filtration system, suggesting that biodegradation is not an important contributor to sulfolane removal in these systems. We conclude that air sparging is a promising approach for enhancing the abundance and activity of aerobic sulfolane-degraders like Rhodoferax to locally stimulate sulfolane biodegradation in situ.

The Effectiveness of Biostimulation, Bioaugmentation and Sorption-Biological Treatment of Soil Contaminated with Petroleum Products in the Russian Subarctic

The effectiveness of different bioremediation methods (biostimulation, bioaugmentation, the sorption-biological method) for the restoration of soil contaminated with petroleum products in the Russian Subarctic has been studied. The object of the study includes soil contaminated for 20 years with petroleum products. By laboratory experiment, we established five types of microfungi that most intensively decompose petroleum hydrocarbons: Penicillium canescens st. 1, Penicillium simplicissimum st. 1, Penicillum commune, Penicillium ochrochloron, and Penicillium restrictum. One day after the start of the experiment, 6 to 18% of the hydrocarbons decomposed: at 3 days, this was 16 to 49%; at 7 days, 40 to 73%; and at 10 days, 71 to 87%. Penicillium commune exhibited the greatest degrading activity throughout the experiment. For soils of light granulometric composition with a low content of organic matter, a more effective method of bioremediation is sorption-biological treatment using peat or granulated activated carbon: the content of hydrocarbons decreased by an average of 65%, which is 2.5 times more effective than without treatment. The sorbent not only binds hydrocarbons and their toxic metabolites but is also a carrier for hydrocarbon-oxidizing microorganisms and prevents nutrient leaching from the soil. High efficiency was noted due to the biostimulation of the native hydrocarbon-oxidizing microfungi and bacteria by mineral fertilizers and liming. An increase in the number of microfungi, bacteria and dehydrogenase activity indicate the presence of a certain microbial potential of the soil and the ability of the hydrocarbons to produce biochemical oxidation. The use of the considered methods of bioremediation will improve the ecological state of the contaminated area and further the gradual restoration of biodiversity.

Phytochemical Profile of Saribus rotundifolius (Anahaw) Crude Extract Found in the University of Eastern Philippines

Phytochemical profiling focuses on the determination of the secondary metabolite present on a sample. Aims: In this research, a phytochemical profiling was done in Saribus rotundifolius (Anahaw) leaves and fruit crude extracts. Methodology: This study determines the secondary metabolites; alkaloid, tannin, flavonoid, cardiac glycoside, saponin, and terpenoid. The samples were cut into pieces and was submerged in an ethanol solution for the extract of crude extract and undergo a rotary evaporator for the separation of the ethanol solvent. Results: The finding showed that the anahaw leaves and fruit crude extract contains secondary metabolites present in both leaves and fruit crude extracts, that can be used in pharmaceutical and drug development, this includes an anti-microbial potential.

Green synthesis and antibiofilm potential of Silver Nanoparticles loaded with Narcissus tazetta L. Extract

Bacterial infections are the leading cause of mortality, due to the paucity of effective drugs. This study aimed to synthesize AgNPs loaded with fresh leaves & bulbs extracts of Narcissus tazetta and evaluate antimicrobial and antibiofilm potential against selected bacterial and fungal isolates using standard microbiological protocols. Different techniques like FTIR spectroscopy, GC-MS, electron microscopy and HPLC were used to characterize the AgNPs. The AgNPs synthesized from crude extract of leaves and bulb were checked and were found effective against all the bacterial isolates except E. coli however, strong biofilm inhibition potential was observed in case of E.coli. The synthesized AgNPs showed dose dependent zone of inhibition higher for methanol and lower for n-Hexane against both Gram + ve and Gram -ve bacterial strains, exhibiting the anti-microbial potential. Biofilm inhibition was recorded at sub-MIC values against Gram + ve and Gram -ve bacterial strains. Antifungal activity of AgNPs was observed only at a higher concentration against Aspergillus niger, Fusarium oxysporum and Alternaria alternata while Aspergillus terreus was resistant even at higher concentrations. In conclusion, we can say that the plant possesses pronounced antimicrobial potential with a wide range of the bioactive compounds, which can be explored for pharmaceutical purposes.