Potential application of bioemulsifier RAG-1 as an anti-staling agent in flat bread quality.

Bread undergoes physicochemical processes known as 'staling', which limits shelf life and quality. Despite the fact that several chemical emulsifiers have been employed to combat this issue, they may offer risks to human health. In this investigation, the effects of bioemulsan, a natural bioemulsifier (BE), on bread quality and staleness were examined. The yield of emulsan generated by Acinetobacter calcoaceticus RAG-1 was 1.49 g/L. The presence of clear zones around colonies, high emulsification value of 100%, and remaining surface tension below 40 mN/m after heating (at 250 °C for 15-20 min) verified emulsan thermal stability. BE-supplemented bread had a greater moisture percentage than the control, resulting in reduced crumb hardening and improved bread quality during storage as measured by moisture content. The first day after adding 0.5% emulsan, the hardness rose from 90.45 N (for the control) to 150.45 N. Texture analysis showed that although the hardness increased during storage, adding emulsan allowed obtaining bread with clearly softer crumb after 2 and 3 days of baking, especially at 0.5% level (from 215.6 N for the control to 150.5 N for 0.5% BE-enriched bread after 2 days, and from 425.7 to 210.25 N after 3 days). Based on the sensory evaluation results, emulsan did not lead to any unpleasant changes on bread organoleptic parameters. Therefore, using bioemulsifier RAG-1 as a green emulsifier and anti-staling agent found to be more promising.

Methods for Detecting the Environmental Coccoid Form of Helicobacter pylori.

Helicobacter pylori is recognized as the most common pathogen to cause gastritis, peptic and duodenal ulcers, and gastric cancer. The organisms are found in two forms: (1) spiral-shaped bacillus and (2) coccoid. H. pylori coccoid form, generally found in the environment, is the transformed form of the normal spiral-shaped bacillus after exposed to water or adverse environmental conditions such as exposure to sub-inhibitory concentrations of antimicrobial agents. The putative infectious capability and the viability of H. pylori under environmental conditions are controversial. This disagreement is partially due to the fact of lack in detecting the coccoid form of H. pylori in the environment. Accurate and effective detection methods of H. pylori will lead to rapid treatment and disinfection, and less human health damages and reduction in health care costs. In this review, we provide a brief introduction to H. pylori environmental coccoid forms, their transmission, and detection methods. We further discuss the use of these detection methods including their accuracy and efficiency.

Three Tests Used to Identify Non-Culturable Form of Helicobacter pylori in Water Samples.

BACKGROUND: Helicobacter pylori, causing the most common chronic bacterial infection, exist in two forms; bacilli and coccoid. The coccoid form is identified as viable but non-culturable bacteria. OBJECTIVES: The current study aimed to conduct culture, polymerase chain reaction (PCR), and loop-mediated isothermal amplification (LAMP) tests to identify coccoid forms of H. pylori. MATERIALS AND METHODS: The PCR and LAMP tests were optimized using specific primers for glmM gene. The sensitivity and specificity of the tests were determined. The current experimental study was conducted on 10 different strains isolated from clinical cases (H1-H10). The isolates were added to tap water and incubated at three different temperatures for one and two months intervals. After pure-culturing of the bacteria, DNAs were extracted and PCR and LAMP were performed. RESULTS: Ten copies of targeted DNA were required for PCR detection whereas only five copies gave a positive reaction by LAMP assay, with 100% specificity. Of the 10 isolates inoculated in water for one and two months at three different temperatures 4, 22, and 37°C, only three cases (5%) were found positive in the first month; 13 (21.6%) and 29 cases (48.3%) were also positive by PCR and LAMP tests in the first and second months. CONCLUSIONS: Results of the current study confirmed that molecular methods such as PCR and LAMP were much more sensitive, rapid, and specific than culturing to identify non-culturable coccoid forms of H. pylori in water.

Bio-ethanol production by a novel autochthonous thermo-tolerant yeast isolated from wastewater.

BACKGROUND: It has been known for years that ethanol is a bio-fuel to replace fossil fuels. The ethanol industry requires the utilization of micro-organisms capable production with stresses. The purpose of present study was to isolate and characterize ethanologenic yeast with high potential application at high temperature to produce bio-ethanol. METHODS: To isolate ethanologenic yeasts, wastewater samples from a starch producer plant in Varamin, Iran were used. The isolates were identified by molecular characterization. Characteristics of the isolated strains were determined at 30, 35, 40 and 45°C for 48 hours. RESULTS: 50 yeast strains capable of growing well in agar plates in a temperature range of 30-45°C were isolated. Out of the isolated strains, only three strains were screened for their ability to grow at 45°C. Selected yeast, designated as AT-3 strain which showed efficient flocculation capabilities with higher ethanol production and grew faster as compared to the rest of strains in media with 180 g/L glucose at 35°C. The selected yeast was identified as a new strain of Saccharomyces cerevisiae and submitted to the Gene-Bank database. Its' optimum growth temperature was between 35 and 40°C. The results showed that during the bio-ethanol production 2.5 × 10(10) and 8.5 × 10(9) (CFU/mL) were a good indication of strain capability in heat tolerance. Also, ethanol produced at a raise of 6.9% and 6.85% (w/v) at 35 and 40°C, respectively, whereas glucose-to-ethanol conversion yield was about 75% of the theoretical value. CONCLUSIONS: Results emphasized that the isolated strain identified as Saccharomyces cerevisiae. This specific strain has thermo-tolerant, osmo-tolerant, flocculating capabilities with potential for application in developing a low cost ethanol industry.

Vacuum distillation residue upgrading by an indigenous Bacillus cereus.

BACKGROUND: Biological processing of heavy fractions of crude oils offers less severe process conditions and higher selectivity for refining. Biochemical Processes are expected to be low demand energy processes and certainly ecofriendly. RESULTS: A strain of biosurfactant producing bacterium was isolated from an oil contaminated soil at Tehran refinery distillation unit. Based on selected phenotypic and genotypic characteristic including morphology, biochemical proprety, and 16 SrRNA sequencing identified as a novel strain of Bacillus cereus (JQ178332). This bacterium endures a wide range of pH, salinity and temperature. This specific strain utilizes both paraffin and anthracene as samples of aliphatic and polycyclic aromatic hydrocarbons. The ability of this bacterium to acquire all its energy and chemical requirements from Vacuum Distillation Residue (VR), as a net sample of problematic hydrocarbons in refineries, was studied. SARA test ASTM D4124-01 revealed 65.5% decrease in asphaltenic, 22.1% in aliphatics and 30.3% in Aromatics content of the VR in MSM medium. Further results with 0.9% saline showed 55% decrease in asphaltene content and 2.1% Aromatics respectively. CONCLUSION: Remarkable abilities of this microorganism propose its application in an ecofriendly technology to upgrade heavy crude oils.