Microalgae and Cyanobacteria: How Exploiting These Microbial Resources Can Address the Underlying Challenges Related to Food Sources and Sustainable Agriculture: A Review

For thousands of years, crop production has almost entirely depended on conventional agriculture. However, the reality is changing. The ever-growing population, global climate change, soil degradation and biotic/abiotic stresses are a growing threat to food production and security. Thus, sustainable alternatives to increase crop production for a population projected to reach 9.8 billion by 2050 are a major priority. In addition to vertical and soilless farming, innovative products based on bioresources, including plant growth stimulants, have been a target for sustainable food production. Such solutions have led to the exploitation of microorganisms, including microalgae and cyanobacteria as potential bioresources for food and plant biostimulant products. Microalgae (eukaryotic) and cyanobacteria (prokaryotic) are photosynthetic microorganisms with the capacity to synthesize a vast array of bioactive metabolites from atmospheric CO₂ and inorganic nutrients. The present review outlines the nutritional value of microalgae and cyanobacteria as alternative food resources. The potential aspects of microalgae and cyanobacteria as stabilizers of the net change in soil organic carbon (C) levels for reduced farmland degradation are also highlighted. The applications of microalgae and cyanobacteria as remedies for improved soil structure and fertility, and as enhancers of crop productivity and abiotic stress tolerance in agricultural settings are outlined. This review also discusses the co-cultivation of crops with microalgae or cyanobacteria in hydroponic systems to favor optimum root CO₂/O₂ levels for optimized crop production.

     

Genetic interaction ofDrosophila homologue ofabelson (abl) proto-oncogene (D-abl) andlethal(2)giant larvae (lgl) tumour suppressor gene during embryonic development

TheDrosophila homologue (D-abl) of the mammalianabelson proto-oncogene (c-abl) encodes a cytoplasmic protein tyrosine kinase which localizes to axons of the developing embryonic central nervous system (CNS) and has been shown to be required for redundant functions during axonogenesis. These redundant functions become indispensable when other components of the redundant pathway, such as those encoded bydisabled (dab), fasciclin I (fas I) orfailed axon connection (fax) are removed fromabl mutants. Second-site mutations can thus uncover redundant aspects ofabl-mediated axonogenesis. We used this strategy, and present evidence to suggest a redundant function of the cytoskeletal protein encoded by thelethal(2)giant larvae (lgl) tumour suppressor gene during embryonic axonogenesis. Simultaneous mutation inlgl andabl shifts lethality of the mutations to late embryogenesis while mutation in only one of these genes permits development up to late larval/pupal or pharate adult stages. Thelgl ^-;abl ^- embryos show defective development of the CNS, characterized by loss of axonal commissures and longitudinal axonal tracts. Lethality of the double mutation is aggravated or suppressed bydisabled (dab) orenabled (ena) mutations, which act, respectively, as dominant enhancers or suppressors ofabl. The redundant function oflgl tumour suppressor gene during axonogenesis therefore appears to involve aspects of D-abl-mediated signalling.     

Replication in Drosophila chromosomes

DNA fibre autoradiography of highly polytenized nuclei in salivary glands of Drosophila nasuta larvae reveals two distinct types of active replicons. Type I replicons are longer (mean size=64 m), have a very high rate of fork migration (average rate=0.95 m/min) and generally occur in large arrays often extending over several thousand m. In contrast, the type II replicons are smaller (mean size= 20 m), slow replicating (average rate=0.07 m/min) and occur in short arrays containing only a few closely spaced active replicons. Evidence is presented that type I replicons are active in the early S and type II in the late S. Observations on autoradiographic labelling of partially lysed polytene chromosomes provide evidence for a lack of temporal and spatial agreement in the activation of origin points in homologous regions of the lateral polytene strands; these observations also suggest local variations in levels of polyteny within a chromosome. On the basis of this and other available information on replication in polytene chromosomes the possible roles of the two replicon types in the generation of the different ³H-thymidine labelling patterns of polytene chromosomes are discussed.We take pleasure in dedicating this paper to our inspiring teacher Prof. S.P. Ray Chaudhuri on his completing 75 years of fruitful life     

Chemical mediator of insulin action stimulates lipid synthesis and down regulates the insulin receptors in primary cultures of rat hepatocytes

Incubation of rat liver particulate fraction with insulin causes the release of a substance that stimulates lipid synthesis and down regulates the insulin receptor in primary cultures of isolated rat hepatocytes. This substance may be similar to putative mediator(s) of insulin action which has been shown to modulate the activity of key enzymes of lipid and carbohydrate metabolism in various cell free systems. Our data demonstrate that the mediator of insulin is also biologically active in an intact cell system. Down regulation of the insulin receptor by the mediator supports the concept that this phenomenon is a post binding event of insulin action.     

Studies on the efficacy of some post-service intrauterine infusions on the conception rate of repeat breeding cattle

The efficacy of post-insemination intrauterine infusion of Strep to-penicillin, Lugol's solution, one and two vials of Mastalone-U (Pfizer, Bombay, India, containing a combination of oxytetracycline hydrochloride, oleandomycin phosphate, neomycin sulphate, prednisolone and chlorpheniramine maleate) and distilled water was compared on the basis of conception rate with that of control in repeat breeder cows. The results indicated that there was no significant difference between the treated groups and the control, except that with two vials of Mastalone-U, the conception rate was significantly low (P < 0.05). The results of the present trial suggest that intrauterine infusions for the treatment of repeat breeding cows should not be used indiscriminately.     

Isoelectric focusing in immobilized pH gradients: applications in clinical chemistry and forensic analysis

The applications of isoelectric focusing in immobilized pH gradients in clinical chemistry and forensic analysis are reviewed. Strong emphasis is given to the separation of serum proteins, in particular α₁-acidic glycoprotein, acid phosphatase, alkaline phosphatase, α₁-antitrypsin, apolipoproteins, complement component, factor B, factor XIIIB, group-specific component, lecithin:cholesterol acyltransferase, phosphoglucomutase, prealbumin, protein C and transferrin. The analysis of human parotid salivary proteins is discussed and an assessment is given of the state of the art in thalassaemia screening.     

Parameters of availability of zinc in orchard soils in relation to zinc nutrition of apple

Summary Labile pool, selective distribution coefficient and adsorption maxima of zinc were measured. Labile pool decreased while selective distribution coefficient increased with increasing depth in all soil profiles. The values of adsorption maxima of zinc corresponded to selective distribution coefficient. The relative efficiency of four extractantsviz 0.05M CA(NO₃)₂ 0.1M Mg(NO₃)₂; 0.01M EDTA–NH₄OAc and 0.005M DTPA-triethanolamine mixture in predicting the availability of native soil zinc to apple was tested. The correlation study indicated that all extractants are good index of zinc availability to apple trees. DTPA-extractable zinc is as efficient as its labile pool(E-value) in predicting the availability of native soil zinc to apple trees. This study also suggested that soil profile should be sampled upto a depth of 30–60 cm for providing a better prediction of availability of native soil zinc to apple trees.