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The nutritional requirements and growth characteristics of a biosurfactant-producingRhodococcus bacterium isolated from Kuwaiti soil were determined. Maximum cell yields (6.6 g/l) and biosurfactant production were achieved with a medium containing 2% (v/v)n-paraffin as a carbon and energy source, 0.2% lactose broth, optimal concentrations of nitrogen (nitrate), phosphorus, iron, magnesium and sodium sources, and minimal concentrations of potassium and trace element sources. The optimal pH was 6.8 for surfactant production and optimal temperature was 37°C. The biosurfactant produced after 16 to 33 h growth in a 7 I fermenter decreased both surface tension and interfacial tension of culture broth to below 27 and 1.8 mN/m, respectively, and was effective at critical micelle dilutions of 10(-3). Data on biosurfactant biosynthesis suggest that the product is produced as a primary metabolite and, therefore, could be produced effectively under continuous fermentation conditions.

The contamination of food and feed by Aspergillus has become a global issue with a significant worldwide economic impact. The growth of Aspergillus is unfavourable to the development of food and feed industries, where the problems happen mostly due to the presence of mycotoxins, which is a toxic metabolite secreted by most Aspergillus groups. Moreover, fungi can produce spores that cause diseases, such as allergies and asthma, especially to human beings. High temperature, high moisture, retarded crops, and poor food storage conditions encourage the growth of mold, as well as the development of mycotoxins. A variety of chemical, biological, and physical strategies have been developed to control the production of mycotoxins. A biological approach, using a mixed culture comprised of Saccharomyces cerevisiae and Lactobacillus rhamnosus resulted in the inhibition of the growth of fungi when inoculated into fermented food. The results reveal that the mixed culture has a higher potential (37.08%) to inhibit the growth of Aspergillus flavus (producer of Aflatoxin) compared to either single culture, L. rhamnosus NRRL B-442 and S. cerevisiae, which inhibit the growth by 63.07% and 64.24%, respectively.

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The corrosion inhibition of mild steel in 0.5 M H2SO4 solution has been investigated using electrochemical methods, X-ray diffraction (XRD) and scanning electron microscope (SEM). The adsorption and inhibition action of acid corrosion of mild steel using cetyltrimethylammonium bromide (CTABr) and different halides (NaCl, NaBr and NaI) has shown synergetic effect. The results showed that the protection efficiency (P%) has high values at considerable high concentration of CTABr. However, in the presence of the different halides, the P increases dramatically at low concentration of CTABr. Physisorption was proposed from the the values of ΔGads0. The synergism parameter (Sθ) is found to be greater than unity indicating that the enhanced P% caused by the addition of the halides to the CTABr is due to a co-operative adsorption of both species. Corrosion products phases and surface morphology were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively.

Over recent years, there has been an explosive growth of sample preparation techniques. Sample preparation is in most cases meant to be the isolation online or offline concentration of some components of interest or target analytes. Solid phase extraction (SPE) is a very popular technique nowadays in sample preparation. The principal is quite similar with liquid- liquid extraction (LLE) which involves partition of solutes between two phases. But, there are some differences between them and some benefits and limitations of difference types of SPE technique like presented in this paper.

The objective of this study is to verify potential of various types of microorganisms during spray drying and non-refrigerated storage that can be enhanced substantially by selecting suitable protective colloids. Four selected probiotics tested are Lactbacillus plantarum B13 and B18, which are the bacteria probiotics and Kluyveromyces lactis and Saccharomyces blouradii, non-bacteria probiotics. Two levels of experiment occur starting with formulation study of encapsulation agent followed by the viability study of different probiotics after spray dry and two weeks nonrefrigerated storage. The formulation of 30% of gum Arabic, 15% of gelatin and 45% of coconut oil can homogenize well at least for two hours and can produce acceptable dried product (below 4% of moisture content) at low outlet temperature (70℃ -75℃). K. lactis, S. blouradii gives 2.57% and 2.4% of viability percentage after spray drying process and 25.84% and 2.04% after two weeks nonrefrigerated storage respectively. The colonies of non-probiotics bacteria after both conditions are between 1010 and 106 cfu/mL which is among the accepted level for industrial application. However, the survival of probiotics in a spray-dried form during non-refrigerated storage is higher at low of moisture content compared to others.

In this study, the co-culture bacteria of Clostridium sporogenes and Enterobacter aerogenes were immobilized onto two different support materials: loofah sponge and activated carbon (AC) sponge. Both immobilized co-cultures were used in the batch fermentation of pineapple residues for biohydrogen production. The performance of both immobilized loofah and AC sponge was compared with free cell (FC) co-culture in terms of biohydrogen cumulative production and production rate within 48 hr fermentation time. It was found that the immobilized co-culture on AC sponge produced the highest rate of biohydrogen of 35.9 mmol/hr/Lsubstrate compared to loofah and FC co-culture after 24 hr fermentation. However, in terms of preservation of biohydrogen production rate, loofah as a support showed better consistency in terms of performance for 48 hr fermentation time compared to AC. This study also showed that the pH of substrate has a relation to the optical density (OD600) reduction of the bacteria, which could affect biohydrogen production rate.