Control of sulfidogenic bacteria in produced water from the Kathloni oilfield in northeast India

A full-scale study was conducted to evaluate microbiocide efficacy to control the indigenous sulfide-producing bacterial population in produced water at Kathloni, Oil India Limited (OIL), Assam (northeast India). The sulfide-producing culturable bacterial strains present in produced water of Kathloni oilfield were identified as Anaerobaculum mobile, Garciella nitratireducens, Clostridium sporogenes, Thermosediminibacter oceani, Coprothermobacter sp., Thermodesulfovibrio sp., Thermodesulfobacterium sp., Thermodesulfotobacterium sp., and Caldanaerobacter sp. These strains could produce sulfide in the range of 50–200 mg l^?1 and volatile fatty acids such as acetic acid, propionic acid, isobutyric acid, butyric acid, and isovaleric acid. Out of 10 microbiocides screened, three (sodium hypochlorite, benzyl trimethyl ammonium chloride, and 2-bromo-2-nitropropane-1,3-diol) were selected to control the growth and sulfide production by the aforementioned mixed bacterial species. A strategy was designed in which these three microbiocides were sequentially applied in an oilfield for 132 days. There was no significant difference in the chemical composition of the produced water after the treatment.     

Prevalence of methylenetetrahydrofolate reductase 677 C-T polymorphism among mothers of Down syndrome children

INTRODUCTION:

The relationship between chromosomal non-disjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the polymorphism in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677 C-T in women having Down syndrome (DS) children.

MATERIALS AND METHODS:

The prevalence of these variant genotypes (MTHFR 677 C-T polymorphism) in women having DS children (case mothers) (n = 110) was compared with controls (n = 111) from Punjab. Genotyping was done using the polymerase chain reaction method followed by restriction fragment length polymorphism.

RESULTS:

In the present study, 1.8% of case mothers had TT genotype while none of the control mothers showed this genotype. T allele frequency among cases was 0.13 and 0.11 in controls. The Chi-square value showed a non-significant difference between cases and controls.

CONCLUSION:

No association has been observed between 677 C-T polymorphism and risk of non-disjunction in case mothers. Detection of polymorphisms in more genes of folate pathway is required to find out the exact cause of non-disjunction.     

Antioxidant response and Lea genes expression under exogenous ABA and water deficit stress in wheat cultivars contrasting in drought tolerance

Two wheat (Triticum aestivum) cultivars, C306 (drought tolerant) and PBW343 (drought susceptible) were compared for their response to exogenous ABA, water stress (WS) and combined (ABA plus WS) during their seedlings growth. Their responses were studied in the form of seedlings growth, antioxidant potential of roots and shoots and expression levels of LEA genes in shoots. ABA treatment led to increase in levels of ascorbate, ascorbate to dehydroascorbate ratio, antioxidant enzymes and decreases in levels of dehydroascorbate, malondialdehyde (MDA). Decrease in biomass, ascorbate contents, ascorbate to dehydroascorbate ratios and antioxidant enzymes was more in PBW343 than in C306 under WS. Dehydroascorbate and MDA levels were higher in PBW343 than in C306 under WS. ABA plus WS improved some of these features from their levels under WS in PBW343. Proline contents were not increased significantly under ABA in both cultivars. Out of ten LEA genes studied, six LEA genes were induced more under WS than under ABA in C306 but equally induced in PBW343. Four LEA genes were induced earlier in PBW343 but later in C306. Wdhn13 was induced more under ABA than under WS in C306 while it was non-responsive to both stresses in PBW343.     

Sperm transfer during mating, movement of sperm in the female reproductive tract, and sperm precedence in the common cutworm Spodoptera litura

Abstract. Mating behaviour, sperm transfer and sperm precedence were studied in the moth Spodoptera litura (Fabr.) (Lepidoptera: Noctuidae). There existed a rhythmic, diel pattern of mating behaviour of this moth during the scotophase, presumably set with respect to an endogenous activity rhythm. Approximately 30 min after copulation had started, the formation of the corpus of the spermatophore began in the bursa copulatrix of the female moth, but full inflation of the corpus was not completed until 45–60 min after mating had started. The mature spermatophore contained about 350 eupyrene sperm bundles and a large number of individual (loose) apyrene spermatozoa. The mating status and the age of the male insect influenced the number of sperm transferred to the female within the spermatophore, and also affected the consequent fertility. There was no evidence of sperm reflux within the male tract. Within the female, dissociation of eupyrene sperm bundles was evident within the spermatophore less than 15 min after the completion of mating. Spermatozoa began to move from the bursa (in which the spermatophore is lodged) into the spermatheca 30–45 min after the end of the copulation, and the quantity of sperm in the spermatheca reached a plateau at 90 min after mating. Apyrene sperm reached the spermatheca first, followed by eupyrene sperm. Examination of total (apyrene plus eupyrene) sperm in the female tract showed that 86% of mated females received an apparently normal amount of total sperm from the male. Examination of eupyrene sperm alone showed that 81% of matings resulted in an apparently normal transfer of eupyrene sperm. A small proportion (approximately 8%) of the matings, however, were identified as transferring a clearly subnormal quantity of eupyrene sperm to the spermatheca. The eggs produced as a result of such pairings displayed much reduced fertility (about 43%) compared to those from matings confirmed to have transferred normal quantities of sperm, which showed about 92% fertility. This shows that the availability of eupyrene sperm in the spermatheca may be an important constraint on fertility in normal populations of insects. In the laboratory, S. litura females exhibited multiple matings. Of the females, 93% mated, and the mean frequency of mating was 1.69. Mating with a fertile male led to the oviposition of an increased number of eggs. This effect continued even when the female subsequently mated with an infertile male. Displacement of sperm from previous matings is known to be an important factor in the evolution of multiple mating strategies. Our results on sperm utilization by S. litura indicated that after a second mating, the sperm utilized for subsequent fertilization were almost exclusively from the last mating with little mixing. The proportion of eggs fertilized by sperm from the second mating (P₂) was calculated as 0.95, indicating almost complete sperm precedence from the last mating.     

Heavy metal-induced selection and proliferation of antibiotic resistance: A review

Antibiotic resistance is recognized as a global threat to public health. The selection and evolution of antibiotic resistance in clinical pathogens were believed to be majorly driven by the imprudent use of antibiotics. However, concerns regarding the same, through selection pressure by a multitude of other antimicrobial agents, such as heavy metals, are also growing. Heavy metal contamination co-selects antibiotic and metal resistance through numerous mechanisms, such as co-resistance and cross-resistance. Here, we have reviewed the role of heavy metals as antimicrobial resistance driving agents and the underlying concept and mechanisms of co-selection, while also highlighting the scarcity of studies explicitly inspecting the process of co-selection in clinical settings. Prospective strategies to manage heavy metal-induced antibiotic resistance have also been deliberated, underlining the need to find specific inhibitors so that alternate medicinal combinations can be added to the existing therapeutic armamentarium.     

Structural and functional studies of differentially O‐glycosylated analogs of a thrombin inhibitory peptide – variegin

Variegin is a 32‐amino acid long thrombin inhibitory peptide isolated from the salivary gland extract of tropical bont tick Amblyomma variegatum. It was identified to be O‐glycosylated on its Thr‐14 side chain, and this glycosylated form was 14‐fold more potent than that of its non‐glycosylated form. However, as the identity of this glycosylation remained elusive, the mechanistic details underlying its functional impact are not yet known. In this report, we synthesized four different O‐glycosylated analogs of variegin bearing physiologically relevant sugars on its Thr‐14. Functional characterization of these analogs by enzyme inhibitory kinetics and surface plasmon resonance methods showed that all the synthesized glycopeptides are strong thrombin inhibitors. Structural studies by macromolecular docking identified that the sugar moiety of these peptides can potentially mediate favorable interactions with amino acids at the base of thrombin's autolysis loop. This report, for the first time, describes the impact of differential glycosylation on the function of a thrombin inhibitory peptide and tries to provide structural insights into the relevance of peptide glycosylation in thrombin inhibition. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.     

Long-term stability in biomass and production of terpene indole alkaloids by hairy root culture of Rauvolfia serpentina and cost approximation to endorse commercial realism

The effect of 6 years of cultivation and use of table-sugar (TS) on the biomass/terpene alkaloid productivities and rol gene expression were studied in a hairy root (HR) clone of Rauvolfia serpentina. The media cost could be reduced >94 % by replacing sucrose (SUC) with TS—an unexplored avenue for HR cultivation. The overall productivities increased over long-term cultivation with sugar proving superior to SUC for biomass (24.4 ± 2.11 g/l DW after 40 days to 17.31 % higher) and reserpine (0.094 ± 0.008 % DW after 60 days to 193.8 % more) production. The latter however revealed comparatively better yields concerning ajmaline (0.507 ± 0.048 % DW after 60 days to 61.98 % higher) and yohimbine (0.628 ± 0.062 % DW after 60 days to 38.32 % higher), respectively. PCR amplification of rol genes confirmed long-term expression stability.     

Prevalence of Dyslipidemia in Urban and Rural India: The ICMR–INDIAB Study

Aim

To study the pattern and prevalence of dyslipidemia in a large representative sample of four selected regions in India.

Methods

Phase I of the Indian Council of Medical Research–India Diabetes (ICMR-INDIAB) study was conducted in a representative population of three states of India [Tamil Nadu, Maharashtra and Jharkhand] and one Union Territory [Chandigarh], and covered a population of 213 million people using stratified multistage sampling design to recruit individuals ≥20 years of age. All the study subjects (n = 16,607) underwent anthropometric measurements and oral glucose tolerance tests were done using capillary blood (except in self-reported diabetes). In addition, in every 5th subject (n = 2042), a fasting venous sample was collected and assayed for lipids. Dyslipidemia was diagnosed using National Cholesterol Education Programme (NCEP) guidelines.

Results

Of the subjects studied, 13.9% had hypercholesterolemia, 29.5% had hypertriglyceridemia, 72.3% had low HDL-C, 11.8% had high LDL-C levels and 79% had abnormalities in one of the lipid parameters. Regional disparity exists with the highest rates of hypercholesterolemia observed in Tamilnadu (18.3%), highest rates of hypertriglyceridemia in Chandigarh (38.6%), highest rates of low HDL-C in Jharkhand (76.8%) and highest rates of high LDL-C in Tamilnadu (15.8%). Except for low HDL-C and in the state of Maharashtra, in all other states, urban residents had the highest prevalence of lipid abnormalities compared to rural residents. Low HDL-C was the most common lipid abnormality (72.3%) in all the four regions studied; in 44.9% of subjects, it was present as an isolated abnormality. Common significant risk factors for dyslipidemia included obesity, diabetes, and dysglycemia.

Conclusion

The prevalence of dyslipidemia is very high in India, which calls for urgent lifestyle intervention strategies to prevent and manage this important cardiovascular risk factor.