Mechanism of rice bran lipase inhibition through fermentation activity of probiotic bacteria

Rice bran oil is known as wonder oil and it is the most important vegetable oil in Asia. Rice bran oil is extracted from bran that is the outer hard layer of rice. It is an emerging category in edible oil with a lot of nutritional properties and health benefits. Rice bran oil is heart-friendly, boosts up immunity, and prevents from other diseases occurring commonly in Pakistan. The current study aimed to stabilize rice bran oil through different probiotic isolates and to assess the nutritional content of rice bran oil after stabilization. The study was aimed to inactivate naturally occurring lipases that can hydrolyze oil into glycerol and free fatty acid which is a serious problem that gives it a rancid taste and smell. Antilipase activity was used to inactivate naturally occurring lipases that are a huge threat to the stabilization process. The fermentation process utilizes antilipase activity without affecting the nutritional value of oil. Lactobacillus strains were used for the stabilization of rice bran oil. Rice bran oil was extracted in the Soxhlet apparatus. The probiotic lab isolates Lactobacillus delbrueckii S2, Lactobacillus casei S5 and Lactobacillus plantarum S13 were applied to it to increase its shelf life and prevent oxidative rancidity. The extraction temperature of rice bran oil was maintained above 40 °C to inhibit lipase activity. Rice bran oil samples were stored at refrigeration temperature to arrest lipase activity. Probiotics maintained acidic pH to keep oil stabilization. Qualitative analysis was done to confirm rice bran oil stabilization. Determination of Free Fatty Acid (FFA) and saponification value confirmed that oxidative rancidity of rice bran oil was controlled by probiotics. FFA count was less than 10% and Saponification Value (SV) was 180. GC analysis was performed to analyze the FFA profile. Gas Chromatography results have shown 3 fatty acids. Statistical analysis has shown non-significant effect on different incubation temperatures of Lactobacillus isolates. Among the biological methods of stabilization, the use of probiotics is a novel concept and recommended for commercial application.     

Effect of Plumbago zeylanica extract and certain curing agents on multidrug resistant bacteria of clinical origin

Alcoholic extract of Plumbago zeylanica (root) was tested against multidrug-resistant clinical isolates of bacteria (Salmonella paratyphi, Staphylococcus aureus, Escherichia coli, Shigella dysenteriae and a R-plasmid-harbouring standard strain, E.coli x⁺). The extract exhibited strong antibacterial activity against all test bacteria irrespective of their antibiotic resistance behaviour. Phytochemical analysis of crude extract revealed the presence of flavonoids, saponins and naphthoquinone. A comparative evaluation of R-plasmid elimination from E. coli x⁺ (pUK 651) by the plant extract, DNA intercalating dyes (acridine orange and ethidium bromide) and a DNA gyrase antagonizing drug (pefloxacin) were made. All these agents could cure R-plasmid effectively at their respective sub-MIC concentrations. Maximum plasmid curing was observed by pefloxacin (88%), followed by ethidium bromide (36%), acridine orange (14%) and alcoholic extract of P. zeylanica (14%). Curing of plasmid pUK651 from E. coli x⁺ was confirmed by determining the loss of resistance markers in the cured derivative culture. This revised version was published online in November 2006 with corrections to the Cover Date.     

Antagonistic relationship of NuA4 with the non-homologous end-joining machinery at DNA damage sites

The NuA4 histone acetyltransferase complex, apart from its known role in gene regulation, has also been directly implicated in the repair of DNA double-strand breaks (DSBs), favoring homologous recombination (HR) in S/G2 during the cell cycle. Here, we investigate the antagonistic relationship of NuA4 with non-homologous end joining (NHEJ) factors. We show that budding yeast Rad9, the 53BP1 ortholog, can inhibit NuA4 acetyltransferase activity when bound to chromatin in vitro. While we previously reported that NuA4 is recruited at DSBs during the S/G2 phase, we can also detect its recruitment in G1 when genes for Rad9 and NHEJ factors Yku80 and Nej1 are mutated. This is accompanied with the binding of single-strand DNA binding protein RPA and Rad52, indicating DNA end resection in G1 as well as recruitment of the HR machinery. This NuA4 recruitment to DSBs in G1 depends on Mre11-Rad50-Xrs2 (MRX) and Lcd1/Ddc2 and is linked to the hyper-resection phenotype of NHEJ mutants. It also implicates NuA4 in the resection-based single-strand annealing (SSA) repair pathway along Rad52. Interestingly, we identified two novel non-histone acetylation targets of NuA4, Nej1 and Yku80. Acetyl-mimicking mutant of Nej1 inhibits repair of DNA breaks by NHEJ, decreases its interaction with other core NHEJ factors such as Yku80 and Lif1 and favors end resection. Altogether, these results establish a strong reciprocal antagonistic regulatory function of NuA4 and NHEJ factors in repair pathway choice and suggests a role of NuA4 in alternative repair mechanisms in situations where some DNA-end resection can occur in G1.     

Removal of heavy metals from industrial wastewater using microbial fuel cell

Removal efficiency of gold from a solution of pure tetrachloroaurate ions was investigated using microbial fuel cell (MFC) technology. The effects of type of catholyte solution and initial gold concentration on the removal efficiency were considered. Due to its presence at high levels in the gold wastewater, the effect of copper ions on the removal efficiency of the gold ions was also studied. The effects of pH and initial biomass concentration on the gold removal efficiency was also determined. The results showed that after 5 h contact time, 95% of gold removal efficiency from a wastewater containing 250 ppm of initial gold ions at ambient temperature using 80 g/L yeast concentration was achieved. After 48 h of the cell''s operation under the same condition, 98.86% of AuCl₄ ^– ions were successfully removed from the solution. At initial gold concentration in the waste solution of 250 ppm, pH 2, and initial yeast concentration of 80 g/L, 100% removal efficiency of the gold was achieved. On the other hand, the most suitable condition for copper removal was found at a pH of 5.2, where 53% removal efficiency from the waste solution was accomplished.     

Endogenous production of prothymocyte differentiating activity by phytohemagglutinin-stimulated T-cell-depleted human marrow

The PHA responsiveness of marrow T-cell precursors remains a matter of controversy. We have investigated the capacity of human marrow to proliferate under phytohemagglutinin (PHA) stimulation following extensive removal of mature T cells by complement-dependent cytotoxicity with MBG6 and RFT8 monoclonal antibodies. PHA-induced thymidine uptake by marrow cells occurred with a peak on Days 6-8 of incubation instead of Day 3 for PBL. This peak was observed 48 hr earlier in the presence of PHA-stimulated T-depleted marrow cell supernatants. These supernatants can also promote the growth of mature T-cell colonies from MBG6-, RFT8-, T11-, T3- marrow. However, full colony development requires exogenous interleukin 2 (IL-2). IL-2 could be detected in marrow supernatants but only at very low levels and beyond Days 3 and 4. In contrast Days 1-6 marrow supernatants were equally effective in promoting MBG6-RFT8- marrow cell responsiveness to PHA. We conclude that marrow T-cell precursors are not PHA responsive and that PHA induces the production by marrow non-T cells of a prothymocyte-differentiating activity (PTDA); PTDA can differentiate marrow T-cell progenitors into PHA-responsive T cells; following activation by PHA, these cells undergo limited proliferation induced by IL-2 endogenously released from de novo differentiated T cells. It is suggested that this mechanism may account for extrathymic differentiation of the T-cell lineage in heavily irradiated marrow transplantation recipients.     

Metagenomics analysis of the fecal microbiota in Ring-necked pheasants (Phasianus colchicus) and Green pheasants (Phasianus versicolor) using next generation sequencing

Pheasant reintroduction and conservation efforts have been in place in Pakistan since the 1980 s, yet there is still a scarcity of data on pheasant microbiome and zoonosis. Instead of growing vast numbers of bacteria in the laboratory, to investigate the fecal microbiome, pheasants (green and ring neck pheasant) were analyzed using 16S rRNA metagenomics and using IonS5TMXL sequencing from two flocks more than 10 birds. Operational taxonomic unit (OTU) cluster analysis and phylogenetic tree analysis was performed using Mothur software against the SSUrRNA database of SILVA and the MUSCLE (Version 3.8.31) software. Results of the analysis showed that firmicutes were the most abundant phylum among the top ten phyla, in both pheasant species, followed by other phyla such as actinobacteria and proteobacteria in ring necked pheasant and bacteroidetes in green necked pheasant. Bacillus was the most relatively abundant genus in both pheasants followed by Oceanobacillus and Teribacillus for ring necked pheasant and Lactobacillus for green necked pheasant. Because of their well-known beneficial characteristics, these genus warrants special attention. Bird droppings comprise germs from the urinary system, gut, and reproductive sites, making it difficult to research each anatomical site at the same time. We conclude that metagenomic analysis and classification provides baseline information of the pheasant fecal microbiome that plays a role in disease and health.     

Target size analysis of neurotensin receptors

The neurotensin receptors from rat brain synaptosomal membranes differed in subunit structure from those in rat gastric fundus smooth muscle plasma membranes when studied following photoaffinity labelling or after exposure to cross-linking reagents. However, these two receptors were similar in their recognition properties. In this study we compared the target size of the two receptors by radiation inactivation and observed that the receptors in both tissues had similar target sizes (mean values 103,000 and 108,000 daltons). This suggests that the differences in size observed in biochemical studies may reflect changes occurring during the isolation procedures, or, on the other hand, there might be inherent difference in the subunit structure of these receptors.     

Use of response surface methodology to study the effect of media composition on aflatoxin production by Aspergillus flavus

Aflatoxins are one of the most important secondary metabolites. These extrolites are produced by a number of Aspergillus fungi. In this study, we demonstrate the effect of media components and enhanced aflatoxin yield shown by A. flavus using response surface methodology in response to different nutrients. Different components of a chemically defined media that influence the aflatoxin production were monitored using Plackett–Burman experimental design and further optimized by Box–Behnken factorial design of response surface methodology in liquid culture. Interactions were studied with five variables, namely sorbitol, fructose, ammonium sulfate, KH₂PO₄, and MgSO₄.7H₂O. Maximum aflatoxin production was envisaged in medium containing 4.94 g/l sorbitol, 5.56 g/l fructose, 0.62 g/l ammonium sulfate, 1.33 g/l KH₂PO₄, and 0.65 g/l MgSO₄·7H₂O using response surface plots and the point prediction tool of the DESIGN EXPERT 8.1.0 (Stat-Ease, USA) software. However, a production of 5.25 μg/ml aflatoxin production was obtained, which was in agreement with the prediction observed in verification experiment. The other component (MgSO₄.7H₂O) was found to be an insignificant variable.