Iranian Journal of Biotechnology
Year:2009 | Volume:7 | Issue:2|Papers Count:8

The Streptomycetes sp. SCBT strain Gen Bank accession number EU143270 isolated from the rhizosphere soil of medicinal plants was collected from the Kolli hills of Tamil Nadu, India. The strain Streptomyces is designated as School of Chemical and Biotechnology (SCBT), capable of inhibiting the growth of a wide range of Gram-negative and Gram-positive bacteria. An almost complete 16S rRNA gene sequence of the isolate was generated and compared with sequences of representative Streptomyces spp. The 16S rRNA data supported the classification of the strain within the genus Streptomyces, and showed that the SCBT strain was closely related to Streptomyces albogriseolus ATCC AJ494865 with a sequence similarity of 99%. Despite the high sequence similarity, SCBT was phenotypically different from S. albogrieseolus ATCC AJ494865. When the strain was cultured, its culture broth was extracted with ethyl acetate and the contents of the residue were subjected to Liquid Chromatography Mass Spectrum (LCMS) profiling. The chromatographic purity of the peak exhibiting the antimicrobial activity at a Retention time (RT) of 16.2 min was 48%, and the compound was purified. The mass/change (m/z) value of the peak exhibiting antimicrobial activity at the RT of 16.2 min was 391 isotopic ion peak (M+1).

Seedless barberry (Berberis vulgaris L. var. asperma) is one of the few crops that is only cultivated in eastern parts of Iran. As a new crop there has not been any study to identify phylogenetic relationships of this plant with other related species existing in Iran. In this study, Amplification fragment length polymorphism (AFLP) markers based on four selected primer combinations (EcoRI/Tru1I) were used to evaluate genetic variation and phylogenetic relationship among wild and cultivated barberry populations belonging to north east and eastern Iran. Two other species of ornamental barberry and one species of Mahonia aquifolium were also taken in this study. An Unweighted pair group method with arithmetic averages (UPGMA) dendrogram based on genetic distances clearly clustered each species, confirming phylogenetic relationships at the molecular level. These results can clarify the ambiguity in the relationship between Mahonia and Berberis genera. The heterozygosity index, principle coordinates analysis (PCoA), Fst Index and analysis of molecular variance (AMOVA) revealed a significant difference among wild barberry populations. As expected, observed variation within the cultivated barberry population was very low and close to zero. Moreover, morphological markers were used to evaluate variation and phylogenetic relationships among Berberis populations compared to results from AFLP markers by means of the Mantel correspondence test. No significant value was found by the mantel test between AFLP data and morphological markers. The lack of correlation between AFLP and morphological markers suggests low efficiency of identification key of Flora Iranica for classification and phylogenetic consideration of the Berberis family. Further molecular and morphological investigations are necessary to improve understanding of the relationships within species and genera of the Berberis family.

Lipase from Candida antarctica, fixed on macroporous acrylic resin, has been used for the intermediate production of mono- and diolein by hydrolysis of triolein. The effect of altering concentrations of triolein and glycerol and the function of the molecular sieve on the hydrolysis reaction of triolein were investigated. The highest hydrolysis yield was observed for the utmost concentration of triolein, which gave a hydrolysis optimum at the lower reaction time. Raising the concentration of triolein resulted in a 13.7 times increase in mono-and diolein during reaction period. Addition of glycerol to the reaction mixture had a considerably higher positive effect on the production of monolein than that of diolein. The use of a molecular sieve in the mixture was found to be the most effective environment tested, which demonstrated high activity and excellent selectivity toward the formation of intermediate monolein.

The objective of this study was to determine the polymorphism of bovine b-lactoglobulin (b-LG) gene and its association with milk production traits in Iranian Najdi cattle. Blood samples were collected from 80 Najdi cattle from the Najdi cattle breeding station located in Shoshtar, Khuzestan. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniqus were used for identification of various genotypes. The results indicated that allele frequency of b-LG with regard to the B-allele (0.9125) was higher than that of the A-allele (0.0875). Frequencies of AB and BB genotypes were 0.175 and 0.825, respectively, while the AA genotype was found to be absent. Genotype frequencies were in accordance with the Hardy-Weinberg equilibrium. The effect of b-LG genotypes on milk production traits were analysed using a general linear model (GLM). There was no significant association between different genotypes of b-LG and milk production traits of the analysed cows.

Genetic diversity amongst 21 induced mutant clones tolerant to salinity along with one non-irradiated sensitive clone of banana (Musa acuminata cv. Dwarf Cavendish (AAA)) were studied using morphological and random amplified polymorphic DNA (RAPD) markers. Out of the 30 phenotypic indices screened, 23 were polymorph and two traits, leaf habit and blotches color, were differentiated by non-irradiated clone. RAPDs established 106 major amplified products using 14 primers. Out of 106 markers, eight were monomorph, and the remaining (98) were polymorph. The extent of polymorphism indicated the existence of considerable variation DNA level within induced mutant clones. Primer OPA-02 revealed banding patterns specific to salinity resistant clones. Both morphological and RAPD analyses successfully detected genetic variation within induced mutant clones, RAPD also detected variation between the irradiated and non-irradiated clones, which were morphologically indistinguishable. Results were indicative that induced mutations bear a great potential in improving banana for salinity resistant.

The genetic diversity of 20 Iranian populations of Bunium persicum has been evaluated with random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers. Fresh leaves of seedlings from each population were used for genomic DNA extraction. Analysis of banding patterns of 15 RAPD primers and 17 AFLP primer combinations, revealed 192 (86%) and 228 (75%) polymorphic bands, respectively. The range of similarity coefficients within populations were 0.4-0.82 for RAPD and 0.39-0.96 for AFLP markers. No association was observed between similarity matrices of both the DNA markers. Genetic distance patterns between B. persicum populations, expressed by the RAPD and AFLP cluster analyses were relatively different. The resulting dendrograms based on AFLP and RAPD +AFLP markers were more similar when compared to that derived from RAPD analysis. The AFLPgenerated dendrogram was supported with the highest bootstrap values. The measures of relative genetic distances among populations did not completely correlate with geographical distances of places of their origin. Several populations of black cummin were represented as independent groups in the clusters, showing a high level of genetic diversity and unique genetic background. Knowledge of wide genetic diversity observed in the B. persicum populations provides important information for management of germplasm resources with regard to future domestication and breeding programs.

This study aimed to investigate the contribution of four common DFNB (“DFN” for deafness and “B” for autosomal resessive locus) loci and GJB2 gene mutations (exon 2) in hearing impairment in individuals living in Markazi and Qom provinces of Iran. Forty consanguineous Iranian families with at least three affected individuals in family or pedigree who suffer from an autosomal recessive non-syndromic congenital hearing impairment were the subjects of this study. Blood samples were taken from both hearing and non-hearing individuals, DNA was extracted and amplified by using specific primers for the coding region of GJB2 gene (exon 2). The PCR product of GJB2 gene was then sequenced. Also short tandem repeat (STR) markers amplified by using specific primers for loci DFNB2, DFNB3, DFNB4 and DFNB21. At least 2 microsatellite markers (STR) for each DFNB locus exceeding to 4-6 markers for the linked families were used. The amplified markers were analyzed by conventional Polyacrylamide Gel Electrophoresis followed by silver staining. Six families were homozygous or compound heterozygous for GJB2 mutations and were excluded from further studies. Linkage analysis was carried out for the remaining 34 families by genotyping the flanked STR markers of DFNB2, DFNB3, DFNB4 and DFNB21 loci. Six families showed linkage; including one family to DFNB2, two families to DFNB3 and three families to DFNB4 locus while no family showed linkage to DFNB21 locus. Undoubtedly, the best understanding of the genetic basis of hearing loss in Iranian population will be achieved by performing similar experiments in other provinces and also by analyzing more loci.

The claR of Streptomyces clavuligerus in the clavulanic acid gene cluster encodes a transcriptional regulator that controls clavulanic acid biosynthesis. The main goal of this study was isolation and molecular detection of the claR gene and its cloning in the Streptomyces specific vector (pMA:: hyg). By consideration of the claR gene’s start codon, the specific primers were designed. After genomic DNA extraction from S. clavuligerus, the claR gene was amplified by Polymerase Chain Reaction (PCR). The structure of the amplified claR was confirmed by nested-PCR, PCR-restriction fragment length polymorphism (PCRRFLP), and sequencing. A ligation mixture was prepared with the isolated claR gene and cut pMA::hyg vector. Escherichia coli competent cells were finally transformed with the ligation mixture. Presence of the recombinant vector in the transformed colonies was then confirmed by the colony-PCR procedure. The claR gene was also isolated from S. clavuligerus DSM41826, cloned and sequenced in the same manner. The pMA::hyg vector is a shuttle vector, which exists as a multicopy plasmid in E. coli, and as an integrative plasmid in Streptomyces. Therefore, the newly constructed vectors of this study can be regarded as an appropriate tool for site-directed mutagenesis and gene replacement strategies in S. clavuligerus.