Low-molecular-weight xylanase from Trichoderma viride.

An endo-1,4-beta-xylanase (1,4-beta-D-xylan xylanohydrolase, EC 3.2.1.8) has been isolated from a commercial preparation of Trichoderma viride. The molecular weight was 22,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the pI value was 9.3. The xylanase was a true xylanase without cellulase activity. When the N-terminal amino acid sequence of the first 50 residues was compared with that of a xylanase from Schizophyllum commune, strong evidence for homology was found, with more than 50% amino acid identity. T. viride xylanase also possessed extensive identity with a proposed amino-terminal consensus sequence of xylanases from bacteria.     

Characterization of exopolymers of aquatic bacteria by pyrolysis-mass spectrometry.

Exopolymers from a diverse collection of marine and freshwater bacteria were characterized by pyrolysis-mass spectrometry (Py-MS). Py-MS provides spectra of pyrolysis fragments that are characteristic of the original material. Analysis of the spectra by multivariate statistical techniques (principal component and canonical variate analysis) separated these exopolymers into distinct groups. Py-MS clearly distinguished characteristic fragments, which may be derived from components responsible for functional differences between polymers. The importance of these distinctions and the relevance of pyrolysis information to exopolysaccharide function in aquatic bacteria is discussed.     

Embryo culture of Costus speciosus (Koen.) Sm. to regenerate variable diosgenin yielding clones

Mature embryos of Costus speciosus were excised and cultured on Schenk and Hildebrandt's (1972) nutrient medium containing auxins and cytokinins either alone or in combination. Multiple shoots were obtained when kinetin and indole-3-butyric acid were supplemented each at 0.1 mg 1^–1 concentration. Embryo-derived plantlets were multiplied through propagation of rhizomes and the propagules derived from a single embryo were designated as an embryoclone. Twenty such embryo-clones were maintained in the field. Variations in rhizome biomass yield and diosgenin contents of these embryoclones were noted. Thirty-six percent of the embryo-clones studied were high diosgenin yielding types. Diosgenin contents at the intraclonal level were uniform. The in vitro raised plants were morphologically uniform and indistinguishable from their parent.Abbreviations SH Schenk and Hildebrandt (1972) medium - Kn kinetin - BAP 6-benzylaminopurine - 2,4-D 2,4-dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid - IBA indole-3-butyric acid - IAA indole-3-acetic acid - CA casaminoacids (vitamin free) - TLC thin layer chromatography     

Cellobiose hydrolysis using glutaraldehyde-treated mycelia of Aspergillus terreus Thom

Summary The use of glutaraldehyde-treated mycelial pellets of Aspergillus terreus Thorn as a reusable form of -glucosidase was studied. The -glucosidase activity of these pellets has a pH optimum of 4.8 and as compared to untreated mycelia show decreased leakage of enzyme, higher Vmax, greater half-life at 65°C and increased reusability.     

Microbial transformation of sterols to C19-steroids by Rhodococcus equi

A wild-type strain of Rhodococcus equi, isolated from soil, degraded cholesterol, -sitosterol, stigmasterol and mixed sterois to androst-4-ene-3,17-dione (AD) and androsta-1,4-diene-3,17-dione (ADD). A definite preference for a relatively simply structured cholesterol side chain was observed. Highest specific cholesterol side-chain cleavage was associated with active growth of the culture. Maximum yield of ADD was obtained when sodium acetate and cholesterol were incorporated together in the medium. Specific side-chain cleavage required the presence of 2,2-dipyridyl, an inhibitor of ring cleavage.S. Ahmad and B.N. Johri are with the Department of Microbiology, College of Basic Sciences and Humanities, G.B. Pant University of Agriculture and Technology, Pantriagar 263 145, Nainital, UP, India. P.K. Roy, A.W. Khan and S.K. Basu are at Fermentation Technology Division, Central Drug Research Institute, Lucknow, India.     

Cloning, expression and characterization of ovine interleukins 1 alpha and beta.

Ovine interleukin 1 alpha (IL-1 alpha) c-DNA, obtained by polymerase chain reaction, has been cloned into pTZ18R and pTZ19R. The resulting DNA sequence shows close homology with the bovine sequence. The derived amino-acid sequence shows conserved motifs similar to those observed in all species studied so far. No signal peptide is seen. Northern blots of RNA from lipopolysaccharide (LPS)-stimulated ovine alveolar macrophages show IL-1 beta m-RNA to be produced earlier than and to be more transient than IL-1 alpha m-RNA. c-DNAs coding for the IL-1 alpha proprotein and IL-1 alpha and IL-1 beta mature proteins have been cloned and expressed in the yeast Ty-VLP system as fusion proteins. The resultant IL-1 protein preparations, cleaved from their fusion partners by the action of activated coagulation Factor Xa, are 80-95% pure and show biological activity in standard thymocyte co-mitogen and cartilage degradation assays for IL-1. Some species specificity is observed in that sheep thymocytes are more responsive to ovine rIL-1 than are mouse thymocytes. The presence of a Factor Xa cleavage site in the IL-1 alpha proprotein suggests that Factor Xa may be involved in the processing of ovine IL-1 alpha to its mature form.     

Specific binding of sulphated polymers to ram sperm proacrosin

Sulphated polysaccharides and zona pellucida glycoproteins have been shown to bind non-enzymatically to proacrosin, the protein found within the acrosomal vesicle of mammalian spermatozoa. The mechanism of this interaction has been investigated using ¹²⁵I-fucoidan to probe purified ram sperm proacrosin. Results show that (a) binding of' ¹²⁵I-fucoidan to proacrosin is inhibited only by sulphated polymers and (b) recognition is mediated by poly(sulphate) groups and is largely independent of the composition of the polymer chain. It is suggested that a similar mechanism is responsible for the interaction between proacrosin and zona pellueida glycoproteins during the early stages of fertilization in mammals and this process mediates firm binding of spermatozoa to the egg.     

Detection of Bifidobacterium species by enzymatic methods

The properties of Bifidobacterium strains of human origin were examined by three enzymic tests and the amounts of acetic and lactic acids produced were also quantified. It was evident that two strains of the American Type Culture Collection (ATCC) did not belong to the genus. Moreover, at least one strain of Bifidobacterium added to some milk preparations did not show distinctive characteristics of the genus. It was also shown that most of bifidobacteria studied produced alpha-galactosidase (EC 3.2.1.22) and alpha-glucosidase (EC 3.2.1.20). The presence of alpha-galactosidase could afford a rapid differentiation of bifidobacteria used in some dairy products since this enzyme was not detected in Lactobacillus strains studied.     

Organization of the gene for iso-rANP, a rat B-type natriuretic peptide

Using the polymerase chain reaction and oligonucleotide primers constructed from knowledge of the cDNA sequence we have sequenced the gene for iso-rANP, a peptide of the B-type of atrial natriuretic peptides. The overall organization of the rat iso-ANP gene is the same as that of ANP and BNP consisting of three exons and two introns at relatively similar positions. Iso-rANP and it's gene are more closely related to BNPs than ANP and yet there are significant differences at both the protein and DNA levels. Our results suggest that iso-rANP and BNP are distinct members of the same sub-family (B-type natriuretic peptides) within the family of natriuretic peptide genes.