Biotechnology Reports

An extracellular thermo-alkali stable chitinase was obtained from Streptomyces chilikensis RC1830, a novel actinobacterial strain isolated from the sediments of Chilika lake, India. Purification of the enzyme was carried out by concentrating the enzyme with centrifugal device followed by chromatographic separation by DEAE Sepharose ion exchange resin.The molecular weight of the enzyme was 10.5 kDa as determined by SDS-PAGE. The optimum pH and temperature for the partially purified chitinase was pH 7 and 60 °C...

In order to develop rich new varieties of peony flowers and solve the problems associated with non-synchronised flowering, a study was conducted to investigate pollen viability of fifteen herbaceous peony cultivars. Pollen was stored for more than one year under four storage conditions (4 °C, -4 °C, -20 °C, and -76 °C). In vitro germination and the I2 -KI staining method were used to test pollen viability. For all cultivars, pollen stored at -76 °C showed a significantly slower rate of viability reduction when compared to all the other storage conditions...

Bacillus aerius S1 and Brevibacterium iodinum S2 showed maximum growth at 37 °C and pH 8. B. aerius and B. iodinum could resist Cr6+ upto 30 and 35 mM and biosorption proficiency ( q ) of B. aerius S1 was 19, 27, 52 and 34 mM/g while for B. iodinum S2, it was 39, 50, 23 and 16 mM/g mM/g after 2, 4, 6 and 8 days of incubation. A pronounced rise in antioxidant enzymes activities was determined in B. aerius S1 i.e. POX (963%), CAT (717%), APOX (699%), SOD (683%), and GST (792%). However, in B. iodinum S2, relatively a minor increase was estimated...

Carotenoids are isoprenoid pigments used by pharmaceutical, cosmetic, food and feed industry as antioxidants and colorants. Although traditional sources of carotenoids are fruits, vegetables and chemical synthesis, prospecting for alternative sinks of common and/or unusual carotenoids is important for the development of natural carotenoid industry. In this work, 30 pigmented bacterial strains from Fildes Peninsula in King George Island, Antarctica, were isolated and identified by 16S rRNA gene sequencing and classified in three phyla, Bacteroidetes, Firmicutes and Actinobacteria...

The aim of this study was to characterize culturable rhizosphere and endophytic bacterial isolates isolated from rhizosphere soil and roots of maize plant irrigated with industrial and municipal wastewater in terms of resistance to heavy metals and salinity and plant growth promoting (PGP) traits. Results illustrated that both rhizosphere isolates and endophytic ones had various PGP characteristics in terms of both the number and the production amount of these characteristics. A substantial number of the bacterial isolates (both endophytic isolates and rhizosphere isolates) were tolerant to heavy metals (multi-metal resistant bacteria)...

This study was designed to evaluate the bacterial composition of the Labroides dimidiatus and its surrounding water. Fish and carriage water samples were obtained from corals of the Karah Island in Terengganu Malaysia. DNA was extracted and the bacteria communities on the skin mucus and stomach as well as water sample were classified (to family level) using the 16S rRNA-based metagenomics analysis. 1,426,740 amplicon sequence reads corresponding to 508 total operational taxonomic units were obtained from the three metagenomics libraries in this study...

Industrially, harvesting of the microalgal biomass is a techno-economic tailback, which essentially meant for the algal biomass industry. It is considered energy as well as cost-intensive in view of the fact that the dewatering process during harvesting. In this review chemical reactions involved in the flocculation of microalage biomass via various certain principal organic polymers are focused. Besides, it focuses on natural biopolymers as flocculants to harvest the cultivated microalgae. Commercially, bio-flocculation is suitable and cost-effective in the midst of a range of adopted harvesting techniques and the selection of an appropriate bioflocculant depends on its efficacy on the several microalgae strains like potential biomass fixation, ecological stride and non-perilous nature...

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This mini review overviewed the latest updates on the anaerobic hydrogen fermentation using the granulation technology and the microbiome involved in the process. Additionally, the implication of various reactor design and their microbial changes were compared and provided the new insights on the role of microbiomes for rapid granules formation and long term stable operation in a continuous mode operation. The information provided in this communication would help to understand the key role of microbiomes and their importance in anaerobic hydrogen producing granular systems...

The aim of this study was to determine if the novel anti-streptococcal inhibitors, liamocins, also inhibit biofilm formation by S. mutans and S. sobrinus . S. mutans strain ATCC 25175 and S. sobrinus strain ATCC 33478 were tested for biofilm formation in a rapid microtiter plate (MTP) assay and the effects of added liamocins were determined. This assay measures relative biofilm growth on pin lids. Results were verified in a biofilm flow cell assay, using hydroxyapatite-coated coupons to simulate dental material...

The β-1,4-d-xylanohydrolase is an industry valuable catalytic protein and used to synthesize xylooligosaccharides and xylose. In the current study, β-1,4-d-xylanohydrolase from Geobacillus stearothermophilus KIBGE-IB29 was partially purified up to 9.5-fold with a recovery yield of 52%. It exhibited optimal catalytic activity at pH-7.0 and 50 °C within 5 min. Almost 50% activity retained at pH-4.0 to 9.0 however, 70% activity observed within the range of 40 °C to 70 °C. The β-1,4-d-xylanohydrolase showed a significant hydrolytic pattern with 48...

The study was conducted to evaluate the conditions to enhance the accumulation of lipids and starch in Chlorococcum sp. TISTR 8583 for the production of biofuel. The Chlorococcum sp. TISTR 8583 was cultivated on BG-11 medium under optimized light intensity. The nitrogen limitation (NL) enhanced the accumulation of both starch and lipids and resulted in 34.02% total sugars as compared to 22.57% on nitrogen supplemented (NS) media only. Similarly, the nitrogen supplemented (NS) media produced 17.05% lipids as compared to 29...

Silver nanoparticles play a important role in controlling mosquito population as well as multi drug resistant pathogens without causing much harm to humans. In the present study was focused on green synthesis of silver nanoparticles against dengue causing vector ( Aedes aegypti ) and pathogens affecting humans. The synthesized silver nanoparticle was confirmed using UV- absorption spectrum range obtained at 416 nm, XRD, FTIR and HR-TEM analysis were used to determine the silver nanoparticle morphology and size with ∼6...

In this study, anti-proliferative effects of C. calcitrans extract and its fucoxanthin rich fraction (FxRF) were assessed on human liver HepG2 cancer cell line. Efficacy from each extract was determined by cytotoxicity assay, morphological observation, and cell cycle analysis. Mechanisms of action observed were evaluated using multiplex gene expression analysis. Results showed that CME and FxRF induced cytotoxicity to HepG2 cells in a dose and time-dependent manner. FxRF (IC50 : 18.89 μg.mL-1 ) was found to be significantly more potent than CME (IC50 : 87...

Cold-active lipases are gaining special attention nowadays as they are increasingly used in various industries such as fine chemical synthesis, food processing, and washer detergent. In the present study, an extracellular lipase gene from Yarrowia lipolytica ( LIPY8 ) was cloned and expressed by baculovirus expression system. The recombinant lipase (LipY8p) was purified using chromatographic techniques, resulting in a purification factor of 25.7-fold with a specific activity of 1102.9U/mg toward olive oil. The apparent molecular mass of purified LipY8p was 40 kDa...

Enzymes are highly advantageous compared to dew retting to reach fibers of high and consistent quality. However, no unambiguous insights have been retained from the research, i.e. lacking a clear directive of which enzyme activities are strictly needed. Methods for evaluating enzymatic retting should be standardized, with characterization of chemical, morphological and mechanical properties and analysis of the ease of extraction. Moreover, evaluation should not only be focused on the microscopic level of the fiber but the performance of the resulting composite materials should be assessed as well...

Microaeration can be used to cost-effectively remove in-situ H2 S from the biogas generated in anaerobic digesters. This study is aimed at developing and validating an extension of the Anaerobic Digestion Model n°1 capable of incorporating the main phenomena which occurs during microaeration. This innovative model was implemented and tested with data from a pilot scale digester microaerated for ∼ 200 d. The results showed that despite the model's initial ability to predict the digester's behavior, its predicted performance was improved by calibrating the most influential parameters...

Double-stranded RNA can induce interference processes. The specificity of this system raises the possibility of using dsRNA for therapeutic applications targeting viral diseases. Escherichia coli HT115 (DE3) has been widely used to produce dsRNA; however, the kinetics of dsRNA production and the relationship between dsRNA and biomass remain unknown. Our aims were to study the kinetics of dsRNA production and to improve dsRNA productivity with fed-batch technology. The results revealed that the production of dsRNA was growth-associated...

A methodology to detect peroxidase activity in Opuntia ficus indica cladodes waste extracts was performed and then used towards phenolic compounds. The extracts were able to dimerize three different molecules. Dimeric compounds were produced with yields ranging from 11% to 55%. The influence of H2 O2 concentration was also tested, finding better yields when the peroxide-to-substrate ratio was 1:1. Some water-miscible solvents were used trying to increase overall yields, but no-significant positive results were found...

A protein named TbREF that is localized on rubber particles of the rubber producing dandelion species Taraxacum brevicorniculatum was expressed in tobacco leaves and in yeast. TbREF fused to fluorescence proteins colocalized on globular, hydrophobic structures, most likely lipid droplets. Furthermore, triacylglycerol, sterol and total lipid content of TbREF expressing yeast was determined by photometric analyses of nile red stainings and GC-MS analyses. Therefore, yeast exposed an enhanced nile red fluorescence as well as an increased TAG and sterol content compared to wildtype and vector control...