Background and objectives: Acidosis is a nutritional disorder that is often caused by intake of the high amount of fermentable carbohydrate and an inadequate amount of fiber to induce buffering in the rumen. Hence, a strategy such as the use of microbial additives to prevent acidosis has been suggested. So, this study performed to investigate the effect of using three microbial feed additives (lactate producing and utilizing bacteria and Saccharomyces cerevisiae) in high-concentrate diet on in vitro anaerobic fermentation and digestibility in sheep. Our hypothesis was that the combination of microbial additives compared with individual use and without additives will have a positive effect on in vitro gas production parameters and digestibility in sheep. Materials and methods: For investigating the effect of microbial additives on the in vitro gas production (GP) parameter, ruminal fermentation and digestibility, eight treatments were studied based on as factorial experiment based on a completely randomized design; (1) control (basal diet (70% concentrate and 30% forage) without additive; (CON); (2) basal diet + Megasphaera elsdenii (Me); (3) basal diet + Saccharomyces cerevisiae (SC); (4) basal diet + Lactobacillus fermentum and Lactobacillus plantarum (FP); (5) basal diet + Me + SC (MSC); (6) basal diet + Me + FP (MFP); (7) basal diet + SC + FP (SCFP) and (8) basal diet + Me + SC + FP (MSCFP). Gas production techniques and two step digestion were used to evaluate the effectiveness of experimental treatments. Ruminal fluid was collected from three adult male Arabi sheeps that fed a diet based on forage. Results: Results showed that use of microbial feed additive improved GP and the highest amount of GP was observed in treatment MSCFP (P < 0. 05). However, the lowest amount of methane production was observed in MSC (P < 0. 05). Application microbial feed additives lead to improve in vitro fermentation parameter (OMD and ME) (P < 0. 05). Also, the highest amount of MCP was observed in MSC (P < 0. 05). Digestibility of CP and ADF significantly increased by FP and MSCFP (P < 0. 05). Although, digestibility of NDF numerically increased for SCFP. The concentration of total VFA and acetate significantly increased by MSCFP and CON. But, the highest concentration of propionate and butyrate were observed in MSC and FP. The use of microbial food additives decreased the ratio of acetate to propionate and also the ratio of acetate + butyrate to propionate (P < 0. 05). The highest concentration of ammonia N was observed in MSCFP and SCFP treatments (P < 0. 05). Conclusion: Given the positive results of the experimental treatments on gas production, reduced methane production and nutrient digestibility, the use of these microbial additives may be recommended for testing in high concentrated rations in sheep. Therefore, these FF, SCFP and MSCFP treatments are good candidates for using.

Hyaluronidase has a panoramic use in biotechnology processes and therapy due to its therapeutic, pathophysiological, physiological and biological importance. Since much of the preparations of hyaluronidases are from animal source (bovine and ovine testicular sources) with limited sources of microbial origin, that prompted the authors to screen and isolate a new promising bacterial strain with higher yield followed by its characterization employing detailed taxonomic studies. The newly isolated strain was identified based upon their micro- and macro-morphological, cultural, physiological and biochemical parameters. Twenty isolates from different pathological samples were primarily selected and further screened for their hyaluronidase producing capabilities by measuring reduction in turbidity and hydrolyzed zone of substrate hyaluronic acid. Four isolates showing marked reduction in turbidity (A600 nm) and hydrolyzed zones were selected and subjected to secondary screening by shake flask fermentation. Isolate SII9 (Dental caries specimen) exhibited maximum hyaluronidase activity (117 U/ml) when compared to the reference Streptococcus mitis MTCC*2695 (106 U/ml). A close scrutiny of the literature revealed that the characteristics of our isolate SII9 are mostly identical to S. equi subsp. equisimilis with few differences and thus designated as S. equi SED 9.

Cutinase belongs to the family of serine hydrolases which are capable of hydrolysis of esters and small polyester such as cutin. The cutin of plants is composed of hydroxy and epoxy fatty acids and is substantially imperm-eable to water and only the plant pathogenic bacteria are capable of degrading it. Initially, in order to identify the extent of cutin in cucumber (Cucumis sativus' C. sativus'), golden apples (Golden Delicious apple 'Malus domestica'), red ap-ples (Red Delicious apple 'Malus domestica') and tomatoes (Solanum lycopersicum Mill. Commun' S. lycopersicum'), their fruits were obtained. Cutin was extracted from the fruit skin of each studied specimen and compared by chloro-form-methanol method. Then, isolation of enzyme-producing strains was performed by the use of the specific medium containing cutin and enzyme activity assay. DNA of the specimens was extracted, and PCR were performed with universal primers for 16s DNA. The remainder was devoted to bioinformatic analysis, identification and registration of samples in the gene bank. The results showed that the percentage of extracted cutin in red apple was more than other samples and as a result, red apple are expected to be more resistant against diseases and pests. Also, six cutinase-producer strains of Klebsiella and Enterobacter were isolated with the help of enzyme activity and special culture medium containing cutin, and their 16s DNA region coding sequences were recorded in the GenBank.

The production of pigments from bacteria is significant due to the low cost, high yield and ease of extract compared with other sources. Carotenoids are one of the most important pigments with antioxidant properties which are the precursor of vitamin A synthesis and have antibody overproduction ability, anti-tumor activity and inhibitory effect on the cardiovascular disease. The present study aimed to isolate and identify carotenoid-producing bacteria by highperformance liquid chromatography (HPLC) analysis of their carotenoid pigments. Twenty soil samples were collected from different regions of Tehran. After serial dilution each sample was cultured on BHI agar medium and incubated at 37° C. The pigment-producing bacteria were selected for further identification and their pigments were extracted by methanol. The screening was carried out at two levels: i) selection of the strains by visual color inspection, ii) analysis of the pigment extracts by UV-VIS spectroscopy and HPLC. The isolates were identified by phenotypic methods and their 16S rDNA gene was amplified by PCR method and sequenced. Staphylococcus epidermidis, Micrococcus aloeverae, Citricoccus alkalitolerans, Rhodococcus zopfii, Arthrobacter agilis, Dietzia natronolimnaea and Rhodococcus ruber were identified as carotenoid-producing strains. The highest rate of absorption was observed using UV-VIS analysis in Staphylococcus epidermidis and Dietzia natronolimnaea. The comparison of HPLC analysis with the standard β-carotene curve showed that the carotenoids were beta-carotene. Micro-organisms are a potential source in the production of pigments. In this study we introduced two genera of bacteria (Staphylococcus epidermidis and Dietzia natronolimnaea) with carotenoid-producing ability.

Biosurfactants or surface-active compounds are produced by microoaganisms. These molecules reduce surface tension both aqueous solutions and hydrocarbon mixtures. In this study, isolation and identification of biosurfactant producing bacteria were assessed. The potential application of these bacteria in petroleum industry was investigated. Samples (crude oil) were collected from oil wells and 45 strains were isolated. To confirm the ability of isolates in biosurfactant production, haemolysis test, emulsification test and measurement of surface tension were conducted. We also evaluated the effect of different pH, salinity concentrations, and temperatures on biosurfactant production. Among importance features of the isolated strains, one of the strains (NO.4: Bacillus.sp) showed high salt tolerance and their successful production of biosurfactant in a vast pH and temperature domain and reduced surface tension to value below 40 mN/m. This strain is potential candidate for microbial enhanced oil recovery. The strain4 biosurfactant component was mainly glycolipid in nature.

Background and Objectives: Iron and zinc are two essential micro-nutrients for plant growth and development. Therefore, isolation of siderophores-producing and zinc-solubilizing rhizobacteria involved in bio-availability of these elements is of great interest. Materials and Methods: In this study, soil samples collected from slightly alkaline soil types were screened for high levels of siderophore secretion and zinc solubilization. Results: Among positive colonies, three isolates, named F21A, F37 and F38, were able to secrete siderophore at high levels, ranged between 200 and 300 μ M/liter. A close association was observed between siderophore production capability and growth rate as an indicator of active metabolism. Siderophore production was closely correlated with the level of zinc ion released into the medium as well. All three siderophore producing isolates were able to withstand temperature as high as 37° C, high concentration of NaCl (up to 2. 5%) and a wide range of initial pH from 6 to 9 while hydrolyzing Zn compounds actively. One of the isolates, F21A, tolerated the presence of 200 mgl-1 of zinc. Biochemical and molecular characteristics are indicative that these isolates are Pseudomonas japonica. As experienced in a greenhouse experiment, inoculation with the F21A and F37 isolates significantly increase the plants height, fresh and dry weight of corn with compared to control. Conclusion: These findings demonstrated that the potential of P. japonica strains as plants growth promoting rhizobacteria (PGPR) in iron and zinc deficient soils.

Biosurfactants are surface-active compounds produced by microorganisms. In this study, we collected 60 inguinal area and ear canal samples from cows, sheep, and goats (each, 10 animals) and screened for biosurfactant-producing bacteria. We also determined the genera of culturing strains. Fifty six hemolytic bacterial strains (27, 22 and 7, from cows, sheep and goats, respectively) were isolated. Oil spreading test and bioemulsifying activities were measured for all isolates. The cows’ samples had higher population of positive strains than other animals, so that 5 isolates from inguinal area and 4 from ear canal samples (16.1%) were positive for all tests. For sheep, the numbers were 6 and one (12.5%) while for goats one and two (5.3%), respectively. Totally, 19 isolates (33.9%) were positive for all examinations out of them 12 were gram positives. The microorganisms isolated in this study could well be sources of novel biosurfactants. Further investigation into the composition of the biosurfactants and phylogenetic determination of biosurfactant producing bacteria is suggested.