International Conference on Advances in Biosciences and Biotechnology – ICABB-2019

International Conference on Advances in Biosciences and Biotechnology – ICABB-201

ANTIBACTERIAL ACTIVITY OF PLANT BIOSURFACTANT EXTRACT FROM SAPINDUS MUKOROSSI AND IN SILICO EVALUATION OF ITS BIOACTIVITY

Objective: Natural biosurfactants can replace synthetic surfactants and find applications in cosmetic products. Saponin extracts from Sapindus mukorossi fruits have emulsifying properties and have traditionally been used in hair care treatments. Their utility can be enhanced by studying their antimicrobial activity against common skin and other microorganisms.Methods: Aqueous biosurfactant extracts were prepared from fruits of S. mukorossi. Concentrated and diluted extracts were tested for antimicrobial activity against Micrococcus luteus, Brevibacterium linens, Bacillus subtilis, Staphylococcus epidermidis, Escherichia coli and Pseudomonas fluorescens by the well diffusion method and measuring the zone of inhibition. In silico biological activity of different saponins present in S. mukorossi was studied using the software Prediction of Activity Spectra for Substances (PASS).Results: Concentrated extracts were most active against all the target microorganisms. Gram positive organisms were inhibited more than Gram negative ones. Diluted extracts produced comparable inhibition zones, suggesting that the extent of dilution does not affect the antimicrobial activity further. In silico evaluation showed that major saponin types (Sapindoside B, Sapinmusaponin A, Sapinmusaponin F and Sapinmusaponin N) had antibacterial activity with probable activity to probable inactivity (Pa>Pi) values less than the threshold level of 0.7.Conclusion: Biosurfactant (saponin) extracts from S. mukorossi, can be included in herbal care products not only for their emulsifying properties, but also for their antimicrobial effect. While in silico study showed less than threshold level of antibacterial activity, the combination of all these saponin types together probably contributed to the synergistic antibacterial activity.Â

ENDOPHYTES FROM THE AQUATIC PLANT NELUMBO NUCIFERA: DIVERSITY PROFILE AND ACTIVITY CHARACTERIZATION

Objective: Endophytes represent a niche habitat for the study of novel bio-and chemo diversity. Nelumbo nucifera is an aquatic plant that has not been characterized for endophyte diversity. This study was undertaken with the objective of isolating endophytes from submerged and aerial part of N. nucifera, study the diversity profile of the isolated endophytes and their antimicrobial, antioxidant, and siderophore production capacity.Methods: Endophytes were isolated from aerial and submerged parts of N. nucifera on different media (Starch Casein Nitrate, Glucose Yeast Extract, Nutrient and Potato Dextrose agar). These were further characterized for morphology (colony characteristics, Gram reaction), physiological characteristics (carbon, nitrogen utilization) and activity (antimicrobial, antioxidant, siderophore production). After dereplication, twelve isolates were studied further.Results: All endophyte isolates were Gram-positive bacteria, and one was a fungus. Isolate L-300 showed the highest antioxidant capacity (238 AAE g FW-1) and L-201 least (10 AAE g FW-1. Antimicrobial activity was exhibited against bacteria and fungal targets, with 50% endophytes active against both bacteria and fungi. Isolates L-003 and L-207 exhibited activity against Gram-negative clinical isolates as also fungi. Siderophore production was shown by 58% isolates with L-208 showing maximum activity.Conclusion: This is the first report on profiling of endophytes from N. nucifera. Results show that aquatic plants harbor diverse microbial population. Many promising isolates (such as L-003, L-211, L-214 and L-300) have been characterized in this study and results obtained of antioxidant, antimicrobial and siderophore production capacity demonstrate further utility in polypharmacological studies for identifying compounds of pharmaceutical and other industrial interest.Â

Nitrate reducing bacterial activity in concrete cells of nuclear waste disposal

Leaching experiments of solid matrices (bitumen and cement pastes) have been first implemented to define the physicochemical conditions that microorganisms are likely to meet at the bitumen-concrete interface (see the paper of Bertron et al.). Of course, as might be suspected, the cement matrix imposes highly alkaline pH conditions (10 < pH < 11). The screening of a range of anaerobic denitrifying bacterial strains led us to select Halomonas desiderata as a model bacterium capable of catalyzing the reaction of nitrate reduction in these extreme conditions of pH. The denitrifying activity of Halomonas desiderata was quantified in batch bioreactor in the presence of solid matrices and / or leachate from bitumen and cement matrices. Denitrification was relatively fast in the presence of cement matrix (< 100 hours) and 2 to 3 times slower in the presence of bituminous matrix. Overall, the presence of solid cement promoted the kinetics of denitrification. The observation of solid surfaces at the end of the experiment revealed the presence of a biofilm of Halomonas desiderata on the cement paste surface. These attached bacteria showed a denitrifying activity comparable to planktonic bacterial culture. On the other side, no colonization of bitumen could be highlighted as either by SEM or epifluorescence microscopy. Now, we are currently developing a continuous experimental bioreactor which should allow us a more rational understanding of the bitumen-cement-microbe interactions

Anaerobic utilization of pectinous substrates at extremely haloalkaline conditions by Natranaerovirga pectinivora gen. nov., sp. nov., and Natranaerovirga hydrolytica sp. nov., isolated from hypersaline soda lakes

Anaerobic enrichments at pH 10, with pectin and polygalacturonates as substrates and inoculated with samples of sediments of hypersaline soda lakes from the Kulunda Steppe (Altai, Russia) demonstrated the potential for microbial pectin degradation up to soda-saturating conditions. The enrichments resulted in the isolation of six strains of obligately anaerobic fermentative bacteria, which represented a novel deep lineage within the order Clostridiales loosely associated with the family Lachnospiraceae. The isolates were rod-shaped and formed terminal round endospores. One of the striking features of the novel group is a very narrow substrate spectrum for growth, restricted to galacturonic acid and its polymers (e.g. pectin). Acetate and formate were the final fermentation products. Growth was possible in a pH range from 8 to 10.5, with an optimum at pH 9.5–10, and in a salinity range from 0.2 to 3.5 M Na+. On the basis of unique phenotypic properties and distinct phylogeny, the pectinolytic isolates are proposed to be assigned to a new genus Natranaerovirga with two species N. hydrolytica (APP2T=DSM24176T=UNIQEM U806T) and N. pectinivora (AP3T=DSM24629T=UNIQEM U805T)

Targeted metatranscriptomics of compost derived consortia reveals a GH11 exerting an unusual exo-1,4-β-xylanase activity

Background: Using globally abundant crop residues as a carbon source for energy generation and renewable chemicals production stands out as a promising solution to reduce current dependency on fossil fuels. In nature, such as in compost habitats, microbial communities efficiently degrade the available plant biomass using a diverse set of synergistic enzymes. However, deconstruction of lignocellulose remains a challenge for industry due to recalcitrant nature of the substrate and the inefficiency of the enzyme systems available, making the economic production of lignocellulosic biofuels difficult. Metatranscriptomic studies of microbial communities can unveil the metabolic functions employed by lignocellulolytic consortia and identify new biocatalysts that could improve industrial lignocellulose conversion. Results: In this study, a microbial community from compost was grown in minimal medium with sugarcane bagasse sugarcane bagasse as the sole carbon source. Solid-state nuclear magnetic resonance was used to monitor lignocellulose degradation; analysis of metatranscriptomic data led to the selection and functional characterization of several target genes, revealing the first glycoside hydrolase from Carbohydrate Active Enzyme family 11 with exo-1,4-β-xylanase activity. The xylanase crystal structure was resolved at 1.76 Å revealing the structural basis of exo-xylanase activity. Supplementation of a commercial cellulolytic enzyme cocktail with the xylanase showed improvement in Avicel hydrolysis in the presence of inhibitory xylooligomers. Conclusions: This study demonstrated that composting microbiomes continue to be an excellent source of biotechnologically important enzymes by unveiling the diversity of enzymes involved in in situ lignocellulose degradation

PRECIPITATION OF PHENOLS FROM PAPER INDUSTRY WASTEWATER USING FERRIC CHLORIDE

ABSTRACT The removal of phenols from paper industry wastewater by chemical precipitation using ferric chloride was investigated in the present study. The ferric chloride was able to precipitate out phenols as well as coloring matter from the wastewater. The precipitation was found to be highly dependant on both pH and dose of iron salt used. The phenols removal was effective under highly alkaline conditions above pH 10 and the color removal was effective in the pH range of 3.0-6.0. The chemical precipitation performed at pH 12, using ferric chloride dose of 2.5 g/l, was able to reduce 98% of phenols and 80% of color from the paper industry wastewater. The experiments showed the phenols reduction from 79.5 mg/l to a dischargeable level of 2mg/l after treatment with ferric chloride at pH 12. The study claims that the ferric chloride can be used effectively to remove phenols from paper industry wastewater

A proposal for a quality system for herbal products

Today, there is an increasing worldwide demand for botanicals. Developing countries heavily rely on plant-derived medicines for their primary healthcare. One reason amongst many is the relatively inexpensive process economics and the lack of stringent product governance associated with the exploitation of traditional plant medicines compared with modern medicine. Developed countries impose stringent good manufacturing practices and quality control measures on drug products derived from any manufacturing process, regardless of the primary raw material. However, several factors hamper the full-scale application of traditional plant medicines: lack of implementation of effective quality assurance in the manufacturing process; lack of traceability in the supply chain and associated value additions; and inefficient identification of molecular species that affect the therapeutic efficacy of the final product. There lacks an assessable, causative, and prognostic relationship between the raw materials, the manufacturing process and the final product quality. This article suggests some solutions that may be adopted by the phytodrug industry to widen its global reach and retain its credibility. Primarily among them is the implementation of hazards analysis and critical control point in the manufacturing process and employment of process analytical technology for ensuring minimal deviation from the manufacturing process of phytotherapeutics