s .soleimanian-zad

Cellulases and xylanases are hydrolytic enzymes that randomly cleave the β-1, 4 backbones of the cellulose and arabinoxylans of wheat flour and are widely used in the bakery industry as a dough texture improver in the formulations of flour products. Creating novel sources of a microbial strain using induced gamma irradiation can increase enzyme production for bakery industrial usage. According to this, Co60 gamma irradiation has been used to develop a mutant strain of Trichoderma afroharzianum. Trichoderma mutants were isolated, and the qualitative and quantitative screening were used to evaluate the extracellular enzyme production with the wheat bran waste as a substrate. The best Trichoderma mutant isolate was identified using the DNA barcoding method. The highest xylanase activities were observed in the superior mutant isolate of Trichoderma afroharzianum NAS107-M82, which is approximately 3.3 times higher than its parent strain. The electrophoretic pattern of proteins showed that the exo-glucanase I, endo-glucanase III, and the xylanase I enzymes hydrolyzed the wheat bran, synergistically. Overall, gamma irradiation-induced mutation could be an expedient technique to access such superior mutants for the bioconversion of wheat bran wastes to xylanase enzyme.

Despite unique characteristics of tahini, adequate biotechnical studies have not been carried out on tahini. In recent decades, functional food production such as probiotics has increased because of positive effects on the consumer health. Studies have verified that probiotics do not include appropriate survivability in fat ambiences. Hence, the present study was carried out for the first time with the objective of functional tahini production with appropriate survivability of its probiotics.

Probiotic tahini was produced using encapsulated and free Lactobacillus plantarum subspecies PTCC 1896. Additionally, effects of sorbitan three stearate and glycerol on the oil migration and rheology of tahini were assessed using rheometer and centrifuge. Water/oil emulsification method with sodium-alginate, modified starch and sesame oil was used for the probiotic encapsulation.

In the equal quantity of sorbitan three stearate and glycerol, sorbitan three stearate has shown further effects on oil migration while increased the viscosity significantly. After comparison of 0.25, 0.5 and 0.75% additions of the highlighted compounds to tahini for their effects on oil migration and viscosity, 0.5% glycerol was selected to increase the bacterial survivability. At the end of storage time, the most probiotic survivability belonged to tahini, which contained glycerol and encapsulated probiotics (1.2 × 107).

Lactobacillus plantarum subspecies PTCC 1896 encapsulation via emulsion method and addition of it to tahini containing  0.5% glycerol produced functional tahini with 106–107 CFU/g alive bacteria.

Soil frost heaving causes significant destruction to road pavements, railways, pipelines, and other lifeline infrastructures. The conventional methods for dealing with the soil frost heave are primarily based on using the materials whose production and use are harmful to the environment. Due to the recent ecological concerns, developing novel alternative methods has received much attention. This study aims to investigate the possibility of using the microbially induced calcite precipitation method to control soil frost heave for less pollution introduction to the soil. In this study, the Sporosarcina Pasteurii bacterium was used for calcite precipitation. The influence of three factors in four levels, including bacteria concentration, cementing solution concentration, and curing time, was investigated based on a plan set by Taguchi design of experiment method. The results were obtained by analysis of means and analysis of variance statistical methods and compared with the conventional frost heave reduction methods. The results were presented in terms of heave ratio. Based on the testing results, the heave ratios (frost heave ratios of the treated to untreated samples) were obtained to be in the range of 0.21 to 0.42. The results showed that bacteria concentration was the most influential factor in the total frost heave of the treated soil. The influence of curing time was in second place, and the effect of cementing solution concentration was relatively less. The minimum frost heave was achieved in 108 colony-forming units per milliliter bacteria concentration, 0.6 mole per litre cementing solution concentration, and 21 days of curing. The findings indicated that the used method could be efficiently used to reach the desired objective. The heave ratios obtained by this method were promising to a great extent compared to the conventional methods. The reduction of frost heave due to the application of this method was attributed to the precipitated calcite within the soil voids and was justified by the scanning electron microscopy images of the treated soil samples. This study proved that the proposed method might be utilized as a potential ecological-friendly approach in the future researches.

Plants are valuable sources of different antioxidant and antimicrobial compounds. The composition and structure of the functional groups of essential oils and extracts play an important role in their antioxidant and antimicrobial activity. Prosopis farcta is a spice of Leguminosae family and Mimosoideae subfamily, an aborigine to the dry and semi-dried regions of Asia, Africa and America. In this study, the root extract of Prosopis farcta prepared by soxhlet extractor and ethanol 70% solvent. The extraction yield was estimated at 1.85%. Total phenol and flavonoids compounds were calculated 178.14 ± 0.17 mg Gallic acid/g and 94.33 ± 0.77 mg Quercetin/g, respectively. Phenolic compounds comprised 11.98% of the total chemical composition of the extract. IC50 for root extract and BHT (synthetic antioxidant) was determined 2.45 μg/ml and 1.98 μg/ml, respectively. In the β-carotene-linoleic acid system, the average antioxidant activity reported 39.25% for root extract and 57.13% for the BHT. Among 250, 500 and 1000 ppm concentrations of the extract, 1000 ppm showed the best antioxidant effect in soybean oil for 12 days storage at 50°C. Staphylococcus aureus (with MIC 200 µg/ml and MBC 350 µg/ml) showed the most sensitivity in comparison with the two gram-negative bacteria, Salmonella Typhimurium and Escherichia coli. The results of this study showed that the hydro-ethanolic root extract of Prosopis farcta had suitable antimicrobial and antioxidant activity.