Effect of X-rays on structural, physicochemical and functional properties of gluten protein

The gluten protein was exposed to the X-ray radiations for different time range, comprising 1 and 3 seconds. The objective of this study was to determine the effect of x-ray radiations on the physicochemical properties of gluten protein. Different functional properties of proteins like water and oil holding capacities, protein solubility, emulsification activity, and stability index, foaming action and stability, water solubility, protein, and moisture content, along with SDS PAGE, FTIR, Xeta potential net charge was carried out to evaluate the effect of X-ray radiation on gluten protein. Results showed that the enhancement of water holding capacity up to 38.12%, as well as oil holding capacity up to 35% could be seen, whereas a significant decrease in emulsification activity and stability index, foaming capacity and stability, even protein content could be observed in treated samples. The net charge on protein in water solution was found to increase towards the positive side. The structure of the protein remained unchanged based on no change was observed in SDS PAGE electrograph, FTIR secondary structure region. Hence, X-ray treatment can be a possible way to alter the protein structure for “tailor-made applications” in food industries.

Distribution and molecular characterization of biosurfactant-producing bacteria

Alyousif NA, Luaibi YYYA, Hussein W. 2020. Distribution and molecular characterization of biosurfactant-producing bacteria. Biodiversitas 21: 4034-4040. Biosurfactants (BSs) are biological surface-active compounds produced by several microorganisms with many areas of application, as such become an important product in biotechnology and consequence to be used in industries. In recent years, many researchers pay attention to BSs producers' microorganisms. The present study was aimed to isolate, identify, and screening BS producing bacteria from six various sites in two different cities in Iraq. Four samples were collected from four sites in Basrah governorate and the rest two samples from Al-Garraf oilfield in Thi-Qar governorate. A total of 33 different bacterial isolates were obtained, 20 out of the 33 were found to be biosurfactants producing isolates that detected through the emulsification index (E24%), oil spreading test, and emulsification activity. The isolated bacterial strains were more identified by 16S rRNA gene sequencing. The results showed that the biosurfactants producing isolates belonged to genera Bacillus, Pseudomonas, Enterobacter, Staphylococcus, Acinetobacter, and Aerococcus. Bacillus jeotgali and Aerococcus viridans are reporting as biosurfactant producing bacteria for the first time and Bacillus jeotgali is isolated for first time from crude oil of oilfield reservoir in this study in world. Moreover, six bacterial isolates were identified as new strains and deposited at NCBI Genbank under accession numbers MT261834 (Bacillus subtilis strain IRQNWYA3), MT261835 (Bacillus licheniformis strain IRQNWYB4), MT261836 (Pseudomonas stutzeri strain IRQNWYF2), MT261837 (Pseudomonas zhaodongensis strain IRQNWYF3), MT261838 (Pseudomonas sp. IRQNWYF4) and MT261839 (Bacillus licheniformis strain IRQNWYF5). A2 isolate that was identified as Pseudomonas aeruginosa has shown the highest values of emulsification activity and emulsification index (1.678±0.050 absorbance at 540 nm and 56.6% respectively) that show efficient potential of biosurfactant production. Phylogenetic tree was also constructed in this study based on 16S rRNA gene sequences of biosurfactant-producing bacteria to evaluate their close relationship and evolution between them.

Isolation, Selection and Identification of Polyaromatic Hydrocarbons (PAHs) Degrading Bacteria from Heavy Oil Waste (HOW)-Contaminated Soil

The heavy oil waste (HOW) containing polyaromatic hydrocarbon (PAHs) is a persistent organic pollutants (POPs) that difficult to degrade. The new PAH degrading consortium was investigated from HOW contaminated soil in North Sumatera of Indonesia. The isolation, selection and identification of polyaromatic hydrocarbon degrading bacteria from soil contaminated by HOW was conducted to solve a bioremediation process. The isolation microbes from soil contaminated by HOW was performed using a minimum ONR7a media and followed on marine agar media for purification purposes. From the performed isolation results, 11 isolates were able to degrade PAHs compounds, such as phenanthrene, dibenzothiophene, or fluorene compounds. They grew at pH range of 4.8-8.2 and performed on emulsification activity in paraffin from 0.150-0.662. Three of them showed the best performance on HOW biodegradation capability and then successfully selected and identified as Salipiger sp., Bacillus altitudinis, and Ochrobactrum anthropi. using 16S rDNA. The HOW biodegradation as TPH-degradation were 38.66%, 59.60%, and 47.16%, respectively. Those isolated bacteria could potentially be as bioremediation agents to develop on bioremediation process for soils contaminated by HOW.

Biosurfactants Production Ability of Lactic Acid Bacteria Strains, Emulsification Activity and Cell Adhesion to Hydrocarbons

The paper presents the results of research carried out for screening of 10 lactic acid bacteria strains with antifungal activity for their ability to produce biosurfactants and to select the most performant strains for further biotechnological application as hydrocarbon-degraders in bioremediation of oil-polluted soils. All the strains of lactic acid bacteria were able to form circle displacement area in engine oil 2T with various diameters, confirming the production of biosurfactants in various amounts. Emulsification activity was registered, with values of emulsification index E24 ranging from minimum 25.75% for the strain LAB 132 to maximum 75.93% for the strain LAB 13. Bacterial cells presented adhesion to hydrocarbons (kerosene), degrees of hydrophobicity variable, ranged between 25,57% for LAB 58 and 75,42% for Lpl and formed emulsions stable for over 7 days. Results of the assay of ionic charge revealed the anionic nature of the biosurfactants. Keywords: biosurfactants, lactic acid bacteria, emulsification, hydrophobicity, cell adhesion to hydrocarbons

The potential of indigenous bacteria from oil sludge for biosurfactant production using hydrolysate of agricultural waste

Ni’matuzahroh, Sari SK, Ningrum IP, Pusfita AD, Marjayandari L, Trikurniadewi N, Ibrahim SNMM, Fatimah, Nurhariyati T, Surtiningsih T, Yuliani H. 2019. The potential of indigenous bacteria from oil sludge for biosurfactant production using hydrolysate of agricultural waste. Biodiversitas 20: 1374-1379. Biosurfactants are amphipathic compounds which are useful in various fields of health, industry, and remediation. Biosurfactants are produced by bacteria that grow in hydrocarbon or sugar substrates. Hydrolysis product of agricultural waste can be used as a biosurfactant production medium. This research aims to obtain biosurfactant producing bacteria from Balongan oil sludge, Indonesia. The ability to grow and produce biosurfactant by indigenous bacteria was tested using a medium of Synthetic Mineral Water (SMW) added by 209.3 ppm of rice straw hydrolysis product (RSHP). The growth of bacteria was evaluated through Total Plate Count (TPC) and biosurfactant production was evaluated through measurement of emulsification activity and surface tension. Six indigenous bacteria were capable to produce biosurfactants in the RSHP. Emulsification activity was not detected, but surface tension reduction was founded. The best biosurfactant was indicated by surface tension value of 53.56 mN/m with TPC value of 20.07 CFU/mL at the 5th day of incubation by BP (1) 5. The indigenous bacteria were identified as Propionibacterium BP (1) 1, Propionibacterium BP (1) 3, Bacillus BP (1) 4, Corynebacterium BP (1) 5, Corynebacterium BP (1) 8, and Rothia BP (1) 6. Utilization of sugar as hydrolysis product of agricultural waste is an innovation of raw materials for biosurfactant production.

Comparisons of Functional Properties of Polysaccharides from Nostoc flagelliforme under Three Culture Conditions

Nostoc flagelliforme is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of Nostoc flagelliforme polysaccharides although these have ignored the functional properties. In this study, we extracted and purified three polysaccharides (WL-CPS, NaCl-CPS and Glu-CPS) from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions, respectively, in order to change the physicochemical properties of polysaccharides with the aim of obtaining better functional properties. Both salt stress and mixotrophic culture conditions increased the specific yield of polysaccharides. Their functional properties were comparatively investigated and the results showed that NaCl-CPS exhibited the highest emulsification activity and flocculation capability, which was also higher than that of some commercial products. In contrast, Glu-CPS exhibited the highest water and oil holding capacities, foaming property, intrinsic viscosity and bile acids binding capacity. Our results indicated that both NaCl-CPS and Glu-CPS could be considered to be functional polysaccharides according to their respective characteristics, which have great potential in numerous applications, such as food, pharmaceutical, cosmetic, chemical and mineral industries. These findings also demonstrated the potential application of the proper regulation of culture conditions in the development of polysaccharides with desired functional properties.

Microorganisms Producing Biosurfactant Selection and Characterization of New Discovered Bioemulsifier that will be Used to Create Ecological Heating Production Technology

The chemical synthesis of surface active compounds is economically inefficient. It requires much energy expense, raw materials and harmful reagents. Biological biosynthesis of surface active substances happens in milder conditions without the use of dangerous chemical reagents. The main goal of this work was to select a microorganism strain capable of producing a bioemulsifier with an ability to create a stable water / fuel-oil emulsion that could be used to design a new ecological heating technology. To this end, 3 microorganism strains displaying a high emulsification activity were used. The new discovered surface active substance (SAS) was investigated with different methods (hydrocarbon overlay agar method, emulsification activity determination, microscopic observation). The production of bioemulsifier (BE) was studied by using soluble and insoluble carbon sources. It was found that Arthrobacter sp. Pr82 is the best bioemulsifier producer. Oleic acid was ascertained as the best carbon source for the production of discovered BE.