abdolhamid namaki

Rhizobia are bacteria that have a symbiosis with legumes. Rhizobia that have some capabilities like ACC deaminase and siderophore production in addition to nitrogen fixation are successful competitors in different environmental conditions for production of more nodules. The aim of this study was the screening of ACC deaminase and siderophore producing Rhizobia.
For screening of ACC deaminase producing rhizobia, all isolates were cultured on M9 medium with two different nitrogen sources, ACC and NH4Cl, and M9 medium without nitrogen source was considered as a control treatment. ACC deaminase producing Rhizobia were identified based on statistical comparison of growth rate on M9 medium with ACC against other mediums. Chrome Azurol S (CAS) liquid assay was used for siderophore producing Rhizobia. All treatments repeated two times and all data analyzed in the base of the completely randomized design. 16S rRNA gene sequencing was used for identifying the best ACC deaminase and siderophore producing strain.
14 isolates of Rhizobium were used for screening of ACC deaminase and siderophore producing isolates. Results showed that just R8 strain was isolated with the capability of ACC deaminase production. This isolate could have better growth on M9 with ACC than two other mediums. In the next experiment, it was determined that 8 isolates are siderophore producing rhizobia based on CAS liquid assay. The result showed that R12 isolate could produce more siderophore than others. According to 16S rRNA gene sequencing, R8 and R12 isolates identified as Sinorhizobium meliloti.
Discussion and The R8 strain that have the capability of ACC deaminase production probability can prevent adverse effects of ethylene during nodulation and abiotic stress. On the other side, R12 that are able to produce siderophore can prevent the growth of soil born pathogen in addition to facilitating nodulation and iron uptake by plants.

A thermophilic strain AMF-07, hydrolyzing carboxymethylcellulose (CMC) was isolated from Kerman hot spring and was identified as Bacillus licheniformis based on 16S rRNA sequence homology. The carboxymethylcellulase (CMCase) enzyme produced by the B. licheniformis was purified by (NH4)2SO4 precipitation, ion exchange and gel filtration chromatography. The purified enzyme gave a single band on SDS-PAGE with a molecular weight of 37 kDa. The CMCase enzyme was highly active and stable over broad ranges of temperature (40-80 ºC), pH (6.0-10.0) and NaCl concentration (10-25%) with an optimum at 70 ºC, pH 9.0 and 20% NaCl, which showed excellent thermostable, alkali-stable and halostable properties. Moreover, it displayed high activity in the presence of cyclohexane (134%) and chloroform (120%). Saccharification of rice bran and wheat bran by the CMCase enzyme resulted in respective yields of 24 and 32 g L-1 reducing sugars. The enzymatic hydrolysates of rice bran were then used as the substrate for ethanol production by Saccharomyces cerevisiae. Fermentation of cellulosic hydrolysate using S. cerevisiae, reached maximum ethanol production about 0.125 g g-1 dry substrate (pretreated wheat bran). Thus, the purified cellulase from B. licheniformis AMF-07 utilizing lignocellulosic biomass could be greatly useful to develop industrial processes.

Nitriles are toxic and hazardous compounds for all organisms which are produced enormously by human being and cause environment pollution. Biodegradation is the best method for Nitrile elimination in sewage. The aim of this study was isolation and identification of native bacteria Acetonitrile-degrading from the sewage of the city of Kerman.
The enrichment and screening of Acetonitrile degrading bacteria was performed in a specific medium containing 1 % Acetonitrile as sole carbon and nitrogen source. Enzyme activity and ammonium production was determined in growth medium using a modification of the phenol/hypochlorite method. Identification of the isolates was undertaken using microbial - biochemical and molecular tests. The optimization of enzyme production was examined. The amount of nitrile and acid were also determined by gas chromatography.
Among three isolated nitrile hydrolyzing producing species (FA3, FA8 and AB19), FA8 isolate showed maximum enzyme productivity. The results of characteristic tests showed that these bacteria belonged to the Pseudomonas sp. Moreover, 16S rRNA sequencing and phylogenetic analyses exhibited that FA11, FA8 and AB19 strains were similar to Pseudomonas Otitidis and Pseudomonas geniculate with 99, 100% homology, respectively. Results of medium optimization of Pseudomonas FA8 strain showed that glucose (10 gL-1) and yeast extract (5 gL-1) in neutral medium strongly supported enzyme production. Gas chromatography results showed that FA8 produced 58% acetic acid at 48 h of incubation.
Discussion and The results demonstrated that Pseudomonas FA8 isolated bacterium is a suitable candidate for degradation of Acetonitrile. This bacterium could be used for treatment of industrial wastewater and sites that contaminated with Acetonitrile.