Although there have been approximately 60 chemical compounds identified as potent fermentation inhibitors in lignocellulose hydrolysate, our research group recently discovered glycolaldehyde as a key fermentation inhibitor during second generation biofuel production. Accordingly, we have developed a yeast S. cerevisiae strain exhibiting tolerance to glycolaldehyde. During this glycolaldehyde study, we established novel approaches for rational engineering of inhibitor-tolerant S. cerevisiae strains, including engineering redox cofactors and engineering the SUMOylation pathway. These new technical dimensions provide a novel platform for engineering S. cerevisiae strains to overcome one of the key barriers for industrialization of lignocellulosic ethanol production. As such, this review discusses novel biochemical insight of glycolaldehyde in the context of the biofuel industry.

The effect of chromosomal aneuploidy on the brewing characteristics of brewery yeasts has not been studied. Here we report that chromosomal aneuploidy in sake brewery yeast () leads to the development of favorable brewing characteristics. We found that pyruvate-underproducing sake yeast, which produces less off-flavor diacetyl, is aneuploid and trisomic for chromosomes XI and XIV. To confirm that this phenotype is due to aneuploidy, we obtained 45 haploids with various chromosomal additions and investigated their brewing profiles. A greater number of chromosomes correlated with a decrease in pyruvate production. Especially, sake yeast haploids with extra chromosomes in addition to chromosome XI produced less pyruvate than euploids. Mitochondrion-related metabolites and intracellular oxygen species in chromosome XI aneuploids were higher than those in euploids, and this effect was canceled in their "petite" strains, suggesting that an increase in chromosomes upregulated mitochondrial activity and decreased pyruvate levels. These findings suggested that an increase in chromosome number, including chromosome XI, in sake yeast haploids leads to pyruvate underproduction through the augmentation of mitochondrial activity. This is the first report proposing that aneuploidy in brewery yeasts improves their brewing profile. Chromosomal aneuploidy has not been evaluated in development of sake brewing yeast strains. This study shows the relationship between chromosomal aneuploidy and brewing characteristics of brewery yeast strains. High concentrations of pyruvate during sake storage give rise to α-acetolactate and, in turn, to high concentrations of diacetyl, which is considered an off-flavor. It was demonstrated that pyruvate-underproducing sake yeast is trisomic for chromosome XI and XIV. Furthermore, sake yeast haploids with extra chromosomes produced reduced levels of pyruvate and showed metabolic processes characteristic of increased mitochondrial activity. This novel discovery will enable the selection of favorable brewery yeasts by monitoring the copy numbers of specific chromosomes through a process that does not involve generation/use of genetically modified organisms.

The present research was undertaken to isolate and characterize petroleum hydrocarbon degrading microbes from ship-breaking yards at Vatiary and Kumira coast in Chittagong. Twenty different petroleum hydrocarbon contaminated composite samples were collected and the total bacterial count was found to vary between 2.7×10 3 cfu/ gm and 1.77×10 7 cfu/ gm. Ten isolates were finally selected through secondary screening by Bushnell-Hass mineral salt medium using kerosene, diesel and engine oil as carbon source. They were provisionally identified and found closely related to the species Listeria monocytogenes, Staphylococcus aureus, Pseudomonas alcaligenes, Listeria grayi, Bacillus pasteurii, Bacillus badius, Bacillus cirroflagellosus, Bacillus circulans, Bacillus brevis and Citrobacter freundii. Greasy spot test was used as the primary indicator of microbial degradation of kerosene, diesel and engine oil. A more specific experiment was carried out to estimate the rate of degradation by the isolates. The highest (96.8%) degradation of diesel was shown by B. brevis, followed by 92%, 88.8% and 84.8% of diesel degradation by the strains of P. alcaligenes, B. cirroflagellosus and C. freundii, respectively. The highest degradation of kerosene (78.26%) and engine oil (43.97%) by S. aureus and L. monocytogenes respectively, were also observed.

This study is conducted on the magneto-hydrodynamics (MHD) boundary layer (BL) heat and mass transfer flow of thermally radiating and dissipative fluid over an infinite plate of vertical orientation with the involvement of induced magnetic field and thermal diffusion. The fluid motion is controlled by uniform suction. The constant heat and mass fluxes at the boundary (plate) have been considered to establish the boundary conditions. The foremost prevailing equations are converted into non-linear dimensionless partial differential equations (PDEs) by applying usual transformations. An efficient explicit finite difference method (FDM) has been performed to reckon the solution of the system of non-linear coupled PDEs in a numerical manner. To ensure the converging nature of the solutions, close observation and heed have been given to stability and convergence schemes. The MATLAB R2015a and Studio Developer FORTRAN 6.6a have been employed for numerical simulation of the schematic model equations. To quest steady-state, an experiment is performed on time simultaneously an experiment on mesh size is ascertained to assure a suitable mesh space. Also, a code verification test has been performed. In addition to that, the computational depictions and discussions have been undertaken on the impacts of significant parametric values for the velocity field, induced magnetic field, temperature, and concentration along with current density and shear stress. The reported results for the present numerical schemes have been compared with published papers in tables and plots. The suction parameter tends to pull down the quantitative measurement of velocity, temperature, and concentration. The induced magnetic field is affected decreasingly by the rising estimation of the magnetic parameter.

Aims: Reducing indiscriminate and over use of antibiotics and chemical preservatives, finding better probiotics and new bacteriocins should get paramount importance which will eventually contribute to save lives of newborn to elderly. Some probiotic Lactobacillus produces bacteriocins or bacteriocin-like-substances (BLS) which may be considered as candidates for biopreservatives. The aims of this study was to find probiotic Lactobacillus and assessing their bacteriocinogenic activity. Methodology and results: Five vegetables were processed and isolated 38 Lactic acid bacteria (LAB) by using De Man Rogosa Sharpe (MRS) medium. Among 38 LAB, only 8 (21%) showed potential antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Salmonella Typhii in agar well diffusion method. Finally, we selected two Lactobacillus species such as Lactobacillus plantarum MG1 and L. delbrueckii MT4 for further in vitro testing. Both isolates showed growth capability at wide range of temperatures (27-45 °C), pH (2-9), NaCl (1-7%), bile salt (0.5-2%) and could produce bacteriocin or BLS; which indicated they have potentiality to be probiotic. Bacteriocin or BLS produced by L. plantarum inhibited E. coli and S. Typhii whereas bacteriocin or BLS of L. delbrueckii inhibited S. aureus, E. coli and S. Typhi. These crude bacteriocin or BLS reduced initial bacterial load of vegetables up to 79% after 48 h while 5% of its mixed with vegetables in room temperature. Conclusion, significance and impact of study: The study showed that our isolated L. plantarum and L. delbrueckii could be used as probiotic to improve public health and their bacteriocin or BLS could be used as biopreservatives.