White-rot fungal conversion of wheat straw to energy rich cattle feed

In order to improve the digestibility and nutrient availability in rumen, wheat straw was subjected to solid state fermentation (SSF) with white-rot fungi (i.e. Pleurotus ostreatus and Trametes versicolor) and the fermented biomass (called myco-straw) was evaluated for biochemical, enzymatic and nutritional parameters. The fungal treatment after 30 days led to significant decrease (P < 0.05) in cell wall constituents viz, acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, lignin and cellulose to the extent of 35.00, 38.88, 45.00, 37.48 and 37.86%, respectively in P. ostreatus fermented straw, while 30.04, 33.85, 39.90, 31.29 and 34.00%, respectively in T. versicolor fermented straw. However, maximum efficiency of fermentation in terms of low carbohydrate consumption per unit of lignin degradation, favoring cattle feed production was observed for P. ostreatus on the 10th day (17.12%) as compared with T. versicolor on the 30th day (16.91%). The myco-straw was found to contain significantly high (P < 0.05) crude protein (CP; 4.77% T. versicolor, 5.08% P. ostreatus) as compared to control straw (3.37%). Metabolizable energy (ME, MJ/kg DM), percent organic matter digestibility (OMD) and short chain fatty acids (SCFAs; mmol) production also increased considerably from control straw (4.40, 29.91 and 0.292) to a maximum up to P. ostreatus fermented straw (4.92, 33.39 and 0.376 on 20th day) and T. versicolor fermented straw (4.66, 31.74 and 0.334 on 10th day), respectively. Moreover, the myco-straw had lower organic carbon and was rich in nitrogen with lower C/N ratio as compared to control wheat straw. Results suggest that the fungal fermentation of wheat straw effectively improved CP content, OM digestibility, SCFAs production, ME value and simultaneously lowered the C/N ratio, thus showing potential for bioconversion of lignin rich wheat straw into high energy cattle feed.     

Assessment of bacterial diversity in agricultural by-product compost by sequencing of cultivated isolates and amplified rDNA restriction analysis

An investigation of bacterial diversity in compost was performed using molecular chronometer in order to reveal its phylogeny. Thirty-three bacterial isolates isolated from compost were analyzed by 16S rRNA gene sequencing which revealed phylogenetic lineage of class Bacilli, γ, β-Proteobacteria, and Actinobacteria. Among these lineages, isolates belonging to class Bacilli consisted of species from genera Staphylococcus, Bacillus, Terribacillus, and Lysinibacillus. From phylum Actinobacteria: Microbacterium barkeri and Kocuria sp. were identified. Other bacterial groups had phylogenetic linkage with genera Comamonas and Acidovorax (class β-Proteobacteria); Serratia, Klebsiella, and Enterobacter (class γ-Proteobacteria). Similar isolates were analyzed through ARDRA. Amplified product of 16S rRNA gene from each isolates was subjected to cleavage by enzymes HpaII, HinfI, and MspI in separate reaction tubes. HpaII generated 2–6 bands ranging from 90–688 bp, HinfI generated 2–5 bands of 71–1,038 bp, and MspI 2–7 bands of 69–793 bp. The restriction patterns from HpaII, HinfI, and MspI were normalized separately and combined by means of pattern recognition software “Diversity Database.” HpaII had highest discrimination index (0.72) than HinfI (0.68) and MspI (0.65), and the combination of all three showed discrimination index (0.69). Numerical analysis of ARDRA patterns demonstrated sufficient phylogenetic information for characterizing bacterial diversity. Phylogenetic relationship obtained among isolates through ARDRA was compared with 16S rRNA gene sequence and ARDRA results showed sufficiently similar 16S rRNA gene sequence analysis, but not an overlapping. It has been observed that ARDRA technique facilitates the identification of bacteria in less than 36 h as compared to traditional 16S rRNA gene sequencing.     

Prognostic significance of CHAC1 expression in breast cancer

Molecular Biology Reports - An emerging component of Unfolded Protein Response (UPR) pathway, cation transport regulator homolog 1 (CHAC1) has been conferred with the ability to degrade...     

Balancing functions of annexin A6 maintain equilibrium between hypertrophy and apoptosis in cardiomyocytes

Pathological cardiac hypertrophy is a major risk factor associated with heart failure, a state concomitant with increased cell death. However, the mechanism governing progression of hypertrophy to apoptosis at the single-cell level remains elusive. Here, we demonstrate annexin A6 (Anxa6), a calcium (Ca²⁺)-dependent phospholipid-binding protein critically regulates the transition of chronic hypertrophied cardiomyocytes to apoptosis. Treatment of the H9c2(2-1) cardiomyocytes with hypertrophic agonists upregulates and relocalizes Anxa6 with increased cytosolic punctate appearance. Live cell imaging revealed that chronic exposure to hypertrophic agonists such as phenylephrine (PE) compromises the mitochondrial membrane potential (ΔΨ_m) and morphological dynamics. Such chronic hypertrophic induction also activated the caspases 9 and 3 and induced cleavage of the poly-(ADP-ribose) polymerase 1 (Parp1), which are the typical downstream events in the mitochondrial pathways of apoptosis. An increased rate of apoptosis was evident in the hypertrophied cardiomyocytes after 48–72 h of treatment with the hypertrophic agonists. Anxa6 was progressively associated with the mitochondrial fraction under chronic hypertrophic stimulation, and Anxa6 knockdown severely abrogated mitochondrial network and dynamics. Ectopically expressed Anxa6 protected the mitochondrial morphology and dynamics under PE treatment, and also increased the cellular susceptibility to apoptosis. Biochemical analysis showed that Anxa6 interacts with Parp1 and its 89 kDa cleaved product in a Ca²⁺-dependent manner through the N-terminal residues (1–28). Furthermore, expression of Anxa6^S13E, a mutant dominant negative with respect to Parp1 binding, served as an enhancer of mitochondrial dynamics, even under chronic PE treatment. Chemical inhibition of Parp1 activity released the cellular vulnerability to apoptosis in Anxa6-expressing stable cell lines, thereby shifting the equilibrium away from cell death. Taken together, the present study depicts a dual regulatory function of Anxa6 that is crucial for balancing hypertrophy with apoptosis in cardiomyocytes.Complex machineries govern the life and death decisions in mammalian cells through a dynamic equilibrium, which is essential for physiological homeostasis.¹ Such equilibrium is critical for cardiac myocytes because of their terminally differentiated states and low proliferative capacities. Stress response in cardiomyocytes often involves a switch between survival and cell death pathways.^{2, 3, 4} Cardiomyocyte hypertrophy is an adaptive response to stress, which may turn maladaptive and fatal,⁵ as evident in cardiovascular disorders that leads to heart failure.⁶ Hypertrophied phenotypes are also associated with a balance between cell growth and programmed cell death.⁷ These processes are aided by several patrolling proteins, which sense and operate to ameliorate the anomalies.^{8, 9} Understanding the dynamics of such signaling events is vital for the development of novel therapeutic strategies.Anxa6 belongs to the annexin family of calcium (Ca²⁺)/phospholipid-binding proteins.¹⁰ A major cardiac annexin,¹¹ Anxa6 has diverse functions ranging from handling intracellular Ca²⁺ signaling, cholesterol transport,¹² Ras inactivation¹³ and vesicular traffic.¹⁴ Anxa6 mostly functions as an intracellular scaffold.¹⁵ Although mice with targeted depletion of the Anxa6 gene remain viable,¹⁶ functional redundancies within the annexin family have been proposed to compensate for the loss of Anxa6 function.^{17, 18} A 10-fold overexpression of Anxa6 targeted to the heart developed cardiomyopathies in mice, whereas cardiomyocytes from Anxa6-knockout mice exhibited increased contractility and altered Ca²⁺ turnover.^{19, 20} Such contradictory findings may indicate participation of Anxa6 in counterbalancing signaling mechanisms. Moreover, end-stage heart failures have been reported to be associated with downregulation of Anxa6, and, in general, Anxa6 has compensatory roles in chronic pathological conditions.^{20, 21, 22} However, the function of differential Anxa6 expression or dynamics in chronic cardiomyocyte hypertrophy is poorly understood.We have reported the interactions of Anxa6 with the sarcomeric α-actinin and its role in cardiomyocyte contractility.²³ Recently, we have characterized a role of Anxa6 in the antihypertrophic signaling via the regulation of atrial natriuretic peptide (ANP) secretion.²⁴ The mechanistic spectrum of Anxa6 in the earlier study was limited to a short-term (24 h) exposure of H9c2 cardiomyocytes to the α1-adrenergic receptor agonist phenylephrine (PE). The dynamics of Anxa6 within this small window yielded valuable insight into the spatiotemporal regulation of hypertrophic signaling. Here, we extended the study to understand the dynamics of Anxa6 under chronic hypertrophic conditions. The mechanodeficient H9c2(2-1) cardiomyocyte line has been instrumental in our study to rule out the contributions of Anxa6 towards contractility,²³ owing to its multidimensional scaffold activity and functional compensations.^{17, 18} The H9c2 cardiomyocytes have been extensively characterized and ARE an established animal origin-free model for studying signal-transduction pathways in cardiomyocytes, including hypertrophy.^{25, 26}Adrenergic stimulation is crucial in compensatory and pathological cardiac hypertrophy, an early state that may proceed towards heart failure.²⁷ Cardiac hypertrophy at advanced stages (chronic) is associated with mitochondrial dysfunction, which also contributes to cardiac decompensation.²⁸ To explore the temporal events under chronic hypertrophy, we analyzed the effects of adrenergic induction on mitochondrial membrane potential (ΔΨm) and morphological dynamics, parameters that are directly correlated with mitochondrial dysfunction and programmed cell death.^{29, 30, 31} Anxa6 has been reported to be associated with mitochondria in some cell types.^{17, 32, 33} In the present study, we aim to understand the functions of Anxa6 under chronic hypertrophic conditions that may progress towards apoptosis.     

Hepatic low density lipoprotein receptor binding and lipid profile in Mastomys natalensis during Plasmodium berghei infection

Plasmodium berghei infection to Mastomys natalensis showed hyper beta-lipoproteinemia. The increase in serum cholesterol is associated with decreased uptake of low density lipoprotein (LDL) by the liver through receptor mediated endocytosis. The membranes prepared from infected M. natalensis exhibit up to 50% decline in high affinity binding sites for human 125I-LDL. Significant increases in serum lipids, cholesterol, triglyceride and lipid peroxide (LPO) contents of liver membrane were observed. Effects of lipid constituents and LPO content of liver membrane in relation to LDL catabolism and other possible mechanisms have been explained.     

Colonisation and mass rearing: learning from others

Mosquitoes, just as other insects produced for the sterile insect technique (SIT), are subjected to several unnatural processes including laboratory colonisation and large-scale factory production. After these processes, sterile male mosquitoes must perform the natural task of locating and mating with wild females. Therefore, the colonisation and production processes must preserve characters necessary for these functions. Fortunately, in contrast to natural selection which favours a suite of characteristics that improve overall fitness, colonisation and production practices for SIT strive to maximize only the few qualities that are necessary to effectively control populations.However, there is considerable uncertainty about some of the appropriate characteristics due to the lack of data. Development of biological products for other applications suggest that it is possible to identify and modify competitiveness characteristics in order to produce competitive mass produced sterile mosquitoes. This goal has been pursued - and sometimes achieved - by mosquito colonisation, production, and studies that have linked these characteristics to field performance. Parallels are drawn to studies in other insect SIT programmes and aquaculture which serve as vital technical reference points for mass-production of mosquitoes, most of whose development occurs - and characteristics of which are determined - in an aquatic environment. Poorly understood areas that require further study are numerous: diet, mass handling and genetic and physiological factors that influence mating competitiveness. Compromises in such traits due to demands to increase numbers or reduce costs, should be carefully considered in light of the desired field performance.     

Phospholipids of wheat chloroplast and its membranes under water stress

Phospholipids showed a differential change in the chloroplast membranes in two cultivars under water stress. Amongst the individual phospholipids, phosphatidyl choline (PC) increased under stress in the low water requiring cultivar C-306 but it decreased in high water requiring cultivar S-308. PC of chloroplast envelope and chloroplast thylakoids showed similar response. Increase in PC content in chloroplasts and its membranes of resistant cultivar may suggest a basis for stress resistance.     

In Situ Bioremediation Potential of an Oily Sludge-Degrading Bacterial Consortium

A field-scale study was conducted in a 4000 m² plot of land contaminated with an oily sludge by use of a carrier-based hydrocarbon-degrading bacterial consortium for bioremediation. The land belonged to an oil refinery. Prior to this study, a feasibility study was conducted to assess the capacity of the bacterial consortium to degrade oily sludge. The site selected for bioremediation contained approximately 300 tons of oily sludge. The plot was divided into four blocks, based on the extent of contamination. Blocks A, B, and C were treated with the bacterial consortium, whereas Block D was maintained as an untreated control. In Block A, at time zero, i.e., at the beginning of the experiment, the soil contained as much as 99.2 g/kg of total petroleum hydrocarbon (TPH). The application of a bacterial consortium (1 kg carrier-based bacterial consortium/10 m² area) and nutrients degraded 90.2% of the TPH in 120 days, whereas in block D only 16.8% of the TPH was degraded. This study validates the large-scale use of a carrier-based bacterial consortium and nutrients for the treatment of land contaminated with oily sludge, a hazardous hydrocarbon waste generated by petroleum industry. Received: 20 October 2000 / Accepted: 22 March 2001