H2S biosynthesis and catabolism: new insights from molecular studies

Hydrogen sulfide (H2S) has profound biological effects within living organisms and is now increasingly being considered alongside other gaseous signalling molecules, such as nitric oxide (NO) and carbon monoxide (CO). Conventional use of pharmacological and molecular approaches has spawned a rapidly growing research field that has identified H2S as playing a functional role in cell-signalling and post-translational modifications. Recently, a number of laboratories have reported the use of siRNA methodologies and genetic mouse models to mimic the loss of function of genes involved in the biosynthesis and degradation of H2S within tissues. Studies utilising these systems are revealing new insights into the biology of H2S within the cardiovascular system, inflammatory disease, and in cell signalling. In light of this work, the current review will describe recent advances in H2S research made possible by the use of molecular approaches and genetic mouse models with perturbed capacities to generate or detoxify physiological levels of H2S gas within tissue

Approaches in biotechnological applications of natural polymers

Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)

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Not AvailableIn Vertisols of the semi-arid tropics lack of optimum soil water and low soil temperature (37 °C) during pod development stage has been a major barrier to realizing yield potential of summer groundnut. Seven field experiments (comparing straw with polythene, 50 μm gauge mulch, duration of retention of polythene mulch, testing the combined effect of straw and polythene mulch, N management in straw mulch and field demonstration) were carried out from 1992 to 1999 in a sequence to identify a suitable mulch material, which was socially and economically acceptable and could overcome soil water and soil temperature related problems for summer groundnut. In general, straw mulch (wheat or paddy) produced more pod (17–24%) and haulm yields (16%) of groundnut than polythene mulch (black or transparent) and no mulch because of favourable soil water and soil temperature, earlier seedling emergences, more flower and mature pods numbers, lower bulk density and less weeds. We observed that groundnut plants showed N deficiency under wheat straw mulch at the early stage (up to 60 days after sowing). However, towards maturity N deficiency occurred at the early stage had no significant negative impact on pod yield of groundnut because the plants recovered N deficiency and had greater chlorophyll content and pod yield. This is presumed to be associated with bio-availability of macro and micronutrient during decomposition of organic mulch. The pod yield of groundnut under black polythene was higher than under transparent polythene. The polythene mulch increased soil temperature by 4–5 °C through out the crop growth (germination to maturity), which increased seeding emergence but was detrimental to pod setting and pod development (soil temperature exceeded 40 °C). Thus, the benefit of polythene was only observed when it was retained up to podding stage, but not up to harvest. The combined application of wheat straw and black polythene out-yielded sole application of wheat straw mulch but the former was 45% less profitable than the later one because of the cost of polythene. Wheat straw mulch was finally demonstrated to the farmer's field. It was found that sacrificing 5 t wheat straw as cattle feed, farmers on return get additional 0.47 t ha−1 legume fodder due to mulching which is nutritionally superior quality fodder in terms of crude protein, phosphorus content, crude fiber, ash and silica content compared to wheat straw as cattle feed. Thus, 16% additional production of highly nutritive groundnut haulm due to mulching has a significant implication on (i) nutritional fodder security, especially during the dry season when green fodder is costly and its availability is limited, and (ii) additional income of Rs. 3935 ha−1 from mulch. These two considerations, apart from solving temperature related problems convinced 32 farmers of Vadhvi and Zanjarda village of Junagadh district, Gujarat for adoption of wheat straw technology for summer groundnut in about 50 ha areas.Not Availabl