Tunicamycin-resistant mutants of Bacillus amyloliquefaciens are deficient in amylase, protease and penicillinase synthesis and have altered sensitivity to antibiotics and autolysis

Mutants of Bacillus amyloliquefaciens resistant to at least 10 micrograms/ml of tunicamycin were isolated and shown to be pleiotropic. The mutants were more resistant to streptomycin, chloramphenicol, kanamycin and neomycin than was the parent strain but less resistant to penicillin G and tetracycline. They were more autolytic, presumably due to an altered cell wall. The mutants produced reduced levels of amylase, penicillinase and both metal and serine protease besides having an enhanced sporulation frequency and being more motile.     

Ectopic expression of an osmotin gene leads to enhanced salt tolerance in transgenic chilli pepper (<Emphasis Type="Italic">Capsicum annum</Emphasis> L.)

Plants, when exposed to abiotic or biotic stress, produce several pathogenesis-related proteins to counteract the effects of stress. Osmotin is one of the important pathogenesis-related proteins induced during several stress conditions. We have developed improved salt stress tolerant transgenic chilli pepper plants (Capsicum annum L. var. Aiswarya 2103) by ectopic expression of the Nicotiana tabaccum osmotin gene using Agrobacterium tumefaciens EHA105 as a vector. Four-week-old chilli pepper leaves were used as an explant and A. tumefaciens EHA105 harboring pBINASCOSM plasmid that contains osmotin gene under the control of CaMV 35S promoter and npt II as a selectable marker was used in co-cultivation. Transgene integration and expression were analyzed using molecular, immunochemical, and biochemical assays. PCR and Southern blot analysis confirmed that osmotin gene has been successfully integrated into the genome of chilli pepper plants. The osmotin gene was stably segregated and expressed in T₂ generation transgenic chilli pepper plants, and it was confirmed by Western blot analysis. Biochemical assays of these putative transgenic plants revealed enhanced levels of chlorophyll, proline, glycinebetaine, APX, SOD, DHAR, MDHAR, GR, and relative water content. Yield potential of the putative transgenic chilli pepper plants was evaluated under salinity stress conditions in a green house. The putative transgenic chilli pepper plants overexpressing the osmotin gene were morphologically similar to wild-type plants and produced 3.32 kg chilli pepper fruits per plant at 300 mM NaCl concentration.     

An enzymic method for the determination of chitin and chitosan in fungal cell walls

The free and N-acetyl glucosamine contents, serving as a measure of the amounts of chitosan and chitin respectively, were determined in the chitinase hydrolysates of the cell wall of a wild strain ofNeurospora crassa. Chitinase, obtained from cultures ofSerratia marcescens, could hydrolyse the cell wall completely apart from being capable of hydrolysing preparations of chitin and chitosan. The free and N-acetyl glucosamines, released by chitinase hydrolysis, were determined by a modified Morgan-Elson reaction carried out in the presence and absence of acetic anhydride. The method is capable of estimating chitin and chitosan contents in as little as 100 μg of cell wall material.     

Genotoxic evaluation of Ara-C by multiple parameters

The cytogenetic effects of the antimetabolite, cytosine arabinoside (Ara-C) are evaluated using in vivo and in vitro test systems and applying multiple parameters. The in vivo assay was carried out on 8-10-week-old inbred Swiss albino male mice using bone marrow as the somatic test system and the cells of testis as the meiotic test system. In vitro human leukocyte cultures were also employed. In vivo experimental doses were computed on surface area basis within the therapeutic dose range and injected intraperitoneally and for in vitro they were calculated on blood volume basis. Evaluation of somatic chromosome mutations included conventional screening for chromosome aberrations, variations in mitotic index and sister-chromatid exchanges (SCEs) by in vivo and in vitro methods besides studies on meiotic test systems using conventional screening for chromosome and sperm-head abnormalities. The quantitative data were subjected to statistical analysis by applying appropriate tests to evaluate their significance. The results of in vivo and in vitro experiments reveal the chromosome mutational activity of the compound. This is further supported by data on SCEs from both systems. However, a comparison of both demonstrated a differential mutagenic response of the drug, more in vivo than in vitro. This is also true for SCEs. Even though the mechanisms involved in causing chromosome aberrations and SCEs are different, the data on both corroborate each other on induction of chromosome mutations.     

A note on the use of cross-linked starch in microbiology with special reference to detecting amylase production

Anilogel-E, a cross-linked starch, can be used with distinct advantages where native starch or soluble starch are conventionally used, e.g. in scoring for amylolytic organisms, as an ingredient of fermentation media, and in enhancing protoplast regeneration. It is particularly useful for the direct visualization of amylase producing micro-organisms on solid media, making prior replication of colonies unnecessary.     

Cell Wall Composition of Neurospora crassa Under Conditions of Copper Toxicity

The mycelia of Neurospora crassa grown in the presence of high concentrations of copper were blue in color, but only on a medium containing inorganic nitrate and phosphate as the nitrogen and phosphate sources, respectively. The cell wall isolate of the blue mycelia contained large amounts (12%) of copper and higher amounts of chitosan, phosphate, and amino groups, with a 42% decrease in the chitin content. Although all the glucosamine of the cell wall of control cultures could be released within 6 h of hydrolysis with acid, that of the blue mycelium required prolonged hydrolysis for 24 h. On removal of copper, the cell wall of the blue mycelium could quantitatively bind again to copper as well as to zinc. Although zinc binding was fivefold greater, copper alone was preferentially bound from a mixture of the two metal ions. Supplementation of iron along with copper in the culture medium resulted in the disappearance of the blue color of the mycelium and restoration of normal growth and composition of the cell wall, probably by limiting the uptake of copper from the medium. The possibility of the cell wall being a specific site of lesion in copper toxicity in the mold is discussed.     

Embryo sac studies in three Indian species ofPolypleurum (Podostemaceae)

New combinations for three species ofPolypleurum have been proposed. The Apinagia type of embryo sac is recorded for the first time in a species ofPolypleurum, P. filifolium. The Dicraea type of embryo sac found inP. dichotomum andP. munnarensis has been reinterpreted and renamed as the Polypleurum type. The embryo sac types met with in the family are discussed. The nucellar plasmodium organizes before the embryo sac attains maturity in all the three investigated species.     

A general synthesis of 4-alkyl/aryl substituted saccharins

A new method for the synthesis of 4-alky/aryl substituted saccharins (2) has been developed. The key steps include conjugate addition/acylation of cyclohexenone (3) and reaction of the resulting β-ketoesters 4 with benzyl mercaptan to give the vinyl sulfides 5 and 6. The latter were converted to the saccharins 2 in high yield.     

Filariasis and malaria sera from Orissa (India) lack human immunodeficiency virus (HIV) antibody reactivity

Reports exist indicating a correlation between seropositivity for human T-lymphotrophic virus (HTLV) antibodies and certain parasitic infections in some parts of the world. In 274 filariasis and 119 malarla sera examined from Orissa, none was reactive in a test for antibodies to human immunodeficiency virus (HIV).The author is with the AIDS Surveillance Unit, Regional Medical Research Centre (Indian Council of Medical Research), Bhubaneswar 751 016, India.     

Identification of a potentially neurotoxic pyridinium metabolite of haloperidol in rats

In vivo metabolic studies have revealed that haloperidol is converted to the corresponding pyridinium metabolite which has been characterized in both urine and brain tissues isolated from haloperidol treated rats. Unlike the corresponding conversion of the structurally related Parkinsonian inducing agent MPTP to the ultimate neurotoxic pyridinium metabolite MPP+, the oxidative biotransformation of haloperidol is not catalyzed by MAO-B. Microdialysis studies in the rat indicate that intrastriatal administration of this pyridinium metabolite is about 10% as effective as MPP+ in causing the irreversible depletion of striatal nerve terminal dopamine. The results point to the possibility that some of the neurological disorders observed in experimental animals and man during the course of chronic haloperidol treatment may be mediated by this pyridinium metabolite.