Improved Production of Xylanase in Pichia pastoris and Its Application in Xylose Production From Xylan

Xylanases with high specific activity has been focused with great interest as a useful enzyme in biomass utilization. The production of recombinant GH11 xylanase (MYCTH_56237) from Myceliophthora thermophila has been improved through N-terminal signal peptide engineering in P. pastoris. The production of newly recombinant xylanase (termed Mtxyn11C) was improved from 442.53 to 490.7 U/mL, through a replacement of α-factor signal peptide with the native xylanase signal peptide segment (MVSVKAVLLLGAAGTTLA) in P. pastoris. Scaling up of Mtxyn11C production in a 7.5 L fermentor was improved to the maximal production rate of 2503 U/mL. In this study, the degradation efficiency of Mtxyn11C was further examined. Analysis of the hydrolytic mode of action towards the birchwood xylan (BWX) revealed that Mtxyn11C was clearly more effective than commercial xylanase and degrades xylan into xylooligosaccharides (xylobiose, xylotriose, xylotetraose). More importantly, Mtxyn11C in combination with a single multifunctional xylanolytic enzyme, improved the hydrolysis of BWX into single xylose by 40%. Altogether, this study provided strategies for improved production of xylanase together with rapid conversion of xylose from BWX, which provides sustainable, cost-effective and environmental friendly approaches to produce xylose/XOSs for biomass energy or biofuels production.

Characterization of brown-black pigment isolated from soil bacteria, Beijerinckia fluminensis

Melanin is a ubiquitous pigment found in most organisms it is a dark-brown or black pigment formed by the oxidation of phenolic compounds. They are negatively charged amorphous compounds having quinone groups. In this study; melanin-producing microorganism was isolated from soil obtained from iron ore mine. The soil was enriched in modified Ashbys glucose broth for 15 days at 30°C further to which it was isolated on modified Ashbys agar at 30°C for seven days; the colonies showing pigmentation were selected for further study. Conditions were optimized for maximal production of melanin pigment. The effect of carbon nitrogen tyrosine and metal salts on pigment production was studied. Alkaline conditions were used to extract the pigment from cells, further characterized by UV-VIS spectroscopy for λ-max. FTIR was done to identify the native functional groups and XRD was performed to determine the melanins structure. TGA analysis was done to check its thermal stability. SEM was carried out to check the size and shape of the melanin pigment. The melanin pigment was also analyzed for UV protectant property which was studied by exposure of both melanized and non-melanized cells to UV light at 254nm. Key words: Beijerinckia fluminensis iron ore soil melanin and UV-protection.

Residual Brewing Yeast as Substrate for Co-Production of Cell Biomass and Biofilm Using Candida maltosa SM4

Candida maltosa was cultivated in the liquid phase of residual brewing yeast, a major brewery residue, to produce biomass and biofilm. Using response surface methodology, the effect of two variables at two different levels was investigated. The independent variables were agitation speed (at 100 and 200 rpm), and aeration (at 1 and 3 L min−1). Aeration was identified to be important for the production of both biomass and biofilm, while agitation was the only factor significantly affecting biofilm production. The maximal production of biofilm (2.33 g L−1) was achieved for agitation of 200 rpm and aeration of 1 L min−1, while the maximum for biomass (16.97 g L−1) was reached for 100 rpm agitation and 3 L min−1 air flow. A logistic model applied to predict the growth of C. maltosa in the exponential phase and the biofilm production, showed a high degree of agreement between the prediction and the actual biomass measured experimentally. The produced biofilms were further characterized using Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA). FTIR allowed the identification of methyl, carbonyl ester and sulfate groups, and revealed the presence of uronic acid moieties and glycosidic bonds. Water-retention ability up to relatively high temperatures was revealed by TGA, and that makes the produced biofilm suitable for production of hydrogels. SEM also gave indications on the hydrogel-forming potential of the biofilm.

Novel Simulation and Optimization for the Production of Green Products I.E., Green Gasoline, Green Diesel and Green Waxes.

During the last decagon, there has been expanding international worry over the rise of anthropogenic CO2 discharge into the Earth’s atmosphere. The application of CO2 into a valuable asset is a major concern. The generation of syn gas and then usage of the syn gas into liquid fuel, seems to be one of the promising options in terms of industrial employment, as it offers several advantages: (a) reduction of CO2 , (b) conversion of gases, specially bio-gas, natural gas, LPG, and etc. and CO2 into syngas (c) producing syngas with H2 /CO2 ratio 1:1.9 to 1:2.1 which may further be used for the generation of valuable petrochemicals. The present research focusses on the gas to liquid conversion using the simulating software, Aspen Plus ®. The outcomes are then subjected to Design Expert ® for calculation of the optimal generation rate. The feedstocks used for the proposed present examination are bio-gas or pyro-gas, natural gas and LPG. The research scheme, gas to liquid conversion is carried out using three steps: (a) gas (feedstock) to syngas from the combination of dry reforming and steam reforming of methane, (b) Fischer Tropsch process to produce long chains of hydrocarbons and (c) usage of unconverted CO and H2 and other alcohol derivates in the CHP unit for the production of electricity. Amongst all the feedstocks natural gas production or generation is maximum followed by bio-gas or pyro-gas and then LPG. Due to non-available resources of natural gas and generation of GHG emission, for countries like India, bio-gas or pyro-gas can be used as a promising sustainable feedstock for reducing GHG emission and global warming. The outcomes of Aspen Plus ® of biogas or pyro-gas are then subjected to Design Expert ® for the prediction of the maximal production. It can be confirmed that with 6997.54 kg/h of biogas flowrate and 99.39% recycling of CO2 , the production of green gasoline, green diesel and green waxes are 565.24 (kg/h), 545.45(kg/h) and 642.68 (kg/h) respectively. The outcomes are in good agreement with the theories, thus proving the process to be a realistic one in nature. Therefore, bringing its viability for India in terms of reduction in CO2 emission and development of gas to liquid conversion process.

Microbiological Production of Isocitric Acid from Biodiesel Waste and Its Effect on Spatial Memory

Within this work, the microbial synthesis of (2R,3S)-isocitric acid (ICA), a metabolite of the nonconventional yeast Yarrowia lipolytica, from biodiesel waste, has been studied. The selected strain Y. lipolytica VKM Y-2373 synthesized ICA with citric acid (CA) as a byproduct. This process can be regulated by changing cultivation conditions. The maximal production of ICA with the minimal formation of the byproduct was provided by the use of a concentration of (NH4)2SO4 (6 g/L); the addition of biodiesel waste to cultivation medium in 20–60 g/L portions; maintaining the pH of the cultivation medium at 6, and degree of aeration between 25% and 60% of saturation. Itaconic acid at a concentration of 15 mM favorably influenced the production of ICA by the selected strain. The optimization of cultivation conditions allowed us to increase the concentration of ICA in the culture liquid from 58.32 to 90.2 g/L, the product yield (Y) by 40%, and the ICA/CA ratio from 1.1:1 to 3:1. Research on laboratory animals indicated that ICA counteracted the negative effect of ammonium molybdate (10−5 М) and lead diacetate (10−7 М) on the learning and spatial memory of rats, including those exposed to emotional stress.

Deficiency in Bhlhe40 impairs resistance toH. polygyrus bakeriand reveals novel Csf2rb-dependent regulation of anti-helminth immunity

ABSTRACTThe cytokines GM-CSF and IL-5 are thought to possess largely divergent functions despite a shared dependence on the common beta (βC) chain to initiate signaling. Although IL-5 is part of the core type 2 cytokine signature and is required for protection against some helminths, it is dispensable for immunity to others, such asHeligmosomoides polygyrus bakeri(H. polygyrus). Whether this is due to compensatory mechanisms is unclear. The transcription factor Bhlhe40 has been shown to control GM-CSF production and is proposed to be a novel regulator of T helper type 2 cells. We have found that Bhlhe40 is required in T cells for a protective memory response to secondaryH. polygyrusinfection.H. polygyrusrechallenge elicited dramatic Bhlhe40-dependent changes in gene and cytokine expression by lamina propria CD4+T cells andin vitro-polarized TH2 cells, including induction of GM-CSF and maximal production of type 2 cytokines including IL-5. βCchain-deficient, but not GM-CSF-deficient, mice rechallenged withH. polygyrushad severely impaired protective immunity. Our results demonstrate that Bhlhe40 is an essential regulator of TH2 cell immunity during helminth infection and reveal unexpected redundancy of βCchain-dependent cytokines.

Preliminary Evaluation of Anti-Listerial Bacteriocin-like Peptide Produced by Enterococcus lactis PMD74 Isolated from Ezine Cheese

Enterococcus lactis PMD74 is a novel strain with a notably high antimicrobial activity. The present study evaluated the anti-listerial effect of a bacteriocin-like peptide (BLIP) produced by E. lactis PMD74 isolated from Ezine cheese (PDO). The strain was screened for its antimicrobial activity against 22 indicator strains using both agar spot and well diffusion methods. We observed that the neutralized cell-free supernatant (CFS) of E. lactis PMD74 exhibited varying levels of antimicrobial activity against both closely and distantly related pathogenic strains, with the highest activity displayed against Listeria monocytogenes strains. Although thermostable and resistant to lysozyme treatment, BLIP could be completely inactivated by trypsin, proteinase K, and α-chymotrypsin treatments. BLIP production starts in the early exponential growth phase of E. lactis PMD74 (3 h incubation, 400 AU mL–1) and reaches its maximal production (6400 AU mL–1) at the end of the exponential growth phase. Moreover, it is stable in the pH range of 2.0 to 7.0. The treatment of cultures of L. monocytogenes ATCC 7644 and Escherichia coli ATCC 26922 with sterilized CFS exhibited bactericidal and bacteriostatic effects, respectively. Furthermore, co-inoculation of L. monocytogenes ATCC 7644 and E. lactis PMD74 in skim milk led to complete loss of viability of L. monocytogenes ATCC 7644. These findings suggest that BLIP produced by E. lactis PMD74 could serve as a promising food preservative agent owing to its bactericidal and bacteriostatic properties.