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[en] Mushrooms contain abundant of bioactive compound (polysaccharides and protein) which have benefit to health include immunomodulatory, anticancer, antioxidant and hypocholesterolemic effect. In this study, Pleurotus flabellatus was produced in submerged culture fermentation (SCF) due to its ability to be produced at higher quantity in a compact space and shorter period compared to the conventional method using solid state fermentation. P. flabellatus mycelium were extracted by hot-water extraction method which included boiling with hot water, addition of ethanol, followed by refrigerated centrifuge and lyophilization. The yield of P. flabellatus polysaccharides was 0.95 %. (author)
[en] A total of 117 acid producing baceria were isolated from grass and silage samples. Almost all isolates, 115 isolates posses homfermentative fermentation. All isolates produced lactic acid in a range of 0.36-2.05%. From their growth and their ability in producing lactic acid, two isolates, a coccus (T3-2-02) and a rod (T3-0-01) were selected for a mixed wild type strains for silage inoculant. After irradiation the wild type strains with gama ray, 51 and 58 isolates of high acid producer were selected from T3-2-02 and T3-0-01 strains, respectively. After testing the growht characteristics and the acid productivity, a coccus strain, MC08 and a rod stain, MR4 were choosen as a mixed irradiated starter culture strains for grass silage fermentation using a 50 dats old Pangola grass (Digitaria eriantha). The experiment was divided into 6 treatments. Treatmet I was the control. Treatmment 2, 4% molasses was added ro the grass. Treatment 3, a mixed wild type strains (T3-2-02+ T3-0-01) was inoculated into the grass. Treatment 4, a mixed irradiated strains (MC08+ MR04) was used. Treatment 5, A mixed wild tpye strains was used and supplemented with 4% molasses. Treatnebt 6, A mixed irradiated strain was assed and supplemented with 4% molasses. The results showed that a qualified silage can be obtained within a week from either the treatment inoculated with starter culture together with4% molasses (T5 and T6) or the treatment supplemented with 4% molasses alone (T2). further more, Silage of the treatments that using starter culture supplemented with 4% molasses gave volatile acid in a requred quantity. Silage of the treatments that inoculated either with a wild type pr a mixed irradiated starter culture posses bether quality than the control treatment. Further more silage that used irradiated starter culture showed a faster ffermentation and higher lactic acid production tha silage that uses wild type starter culture.
[en] Effect of cultural pH and incubation temperature on citric acid yield and kinetic patterns of citric acid fermentation by a natural isolate of aspergillus niger as CA16 and one of its gamma ray induced mutants were studied using cane molasses as growth and fermentation substrate. Mutant strain, 277/30 gave maximum citric acid yield of 85 g/l at pH 3.5 and 28 degree centigrade in molasses medium adjusted to 16% sugar and 25% prescott salt in the medium. Parent strain, CA16 gave a maximum yield of 34 g/l at pH 4.0 and 26 degree centigrade in molasses medium adjusted to 16% sugar and 100% prescott salt in the medium. In kinetic studies, strains showed combination kinetics of citric acid fermentation where product formation is directly related to growth and cell mass and indirectly related to carbohydrate uptake
[en] Study was made on samples of seed culture and fermented wort from Gyogon alcohol distillery. In all samples bacteria contaminants were observed. Samples were cultured on Sabouraud dextrose agar, Czapek Dox agar, and nutrient agar media and broth. The selected colonies were isolated. Biochemical tests for identification were conducted. The yeast and bacteria contaminants were identified by morphological characteristics and biochemical reactions. The yeast isolated and identified from Gyogon alcohol distillery was Sacchacromyces cerevisiae. The bacteria contaminants isolated and identified were Aeromonas sp. and Pseudomonas sp.
[en] To meet the reduction of the emission of CO2 imposed by the Kyoto protocol, hydrogen should be produced from renewable primary energy. Besides the indirect production of hydrogen by electrolysis using electricity from renewable resources, such as sunlight, wind and hydropower, hydrogen can be directly produced from biomass. At present, there are two strategies for the production of hydrogen from biomass: the thermochemical technology, such as gasification, and the biotechnological approach using micro-organisms. Biological hydrogen production delivers clean hydrogen with an environmental-friendly technology and is very suitable for the conversion of wet biomass in small-scale applications, thus having a high chance of becoming an economically feasible technology. Many micro-organisms are able to produce hydrogen from mono- and disaccharides, starch and (hemi)cellulose under anaerobic conditions. The anaerobic production of hydrogen is a common phenomenon, occurring during the process of anaerobic digestion. Here, hydrogen producing micro-organisms are in syn-trophy with methanogenic bacteria which consume the hydrogen as soon as it is produced. In this way, hydrogen production remains obscure and methane is the end-product. By uncoupling hydrogen production from methane production, hydrogen becomes available for recovery and exploitation. This study describes the use of extreme thermophilic bacteria, selected because of a higher hydrogen production efficiency as compared to mesophilic bacteria, for the production of hydrogen from renewable resources. As feedstock energy crops like Miscanthus and Sorghum bicolor and waste streams like domestic organic waste, paper sludge and potato steam peels were used. The feedstock was pretreated and/or enzymatically hydrolyzed prior to fermentation to make a fermentable substrate. Hydrogen production by Caldicellulosiruptor saccharolyticus, Thermotoga elfii and T. neapolitana on all substrates was observed. Nutrient requirements and inhibitory effects differed depending on the strain and the feedstock applied. Fermentations on a larger scale under controlled conditions allowed accurate determinations of hydrogen yields and hydrogen production rates for these extreme thermophilic microorganisms. The first results of a new FP 6 Integrated Project 'Hyvolution' (start date 01/01/2006; co-ordinated by Agro-technology and Food Innovations) will be presented. This IP is aimed at the development of a blue-print for an industrial bio-process for decentralized hydrogen production from locally produced biomass. (authors)
[en] Polyhydroxyalkanoates (PHAs) have been produced by various bacteria as natural polymers stored in bacterial cells as a source of carbon and energy. They are currently preferred biomaterials for use in many industrial fields instead of conventional non-degradable plastics. Due to their unique properties they can reduce pollution caused by the increasing global polymer demand. Pseudomonas species have been chosen as PHAs producers in many recent studies. Being metabolically versatile and possessing a remarkable tolerance to a wide range of carbon sources, these bacteria have become an efficient cell factory for PHAs production. Currently, attention is focused on the design of Pseudomonas strains to increase their ability to accumulate PHAs in the cell and modifying their biosynthetic pathways to obtain strains with modified compositions and improved properties. This article discusses the current state of knowledge of polyhydroxyalkanoates synthesized by Pseudomonas species which are industrially important microorganisms. This review provides an overview of recent trends towards PHA production, focusing on the utilization of low-cost carbon sources, fermentation strategies, PHAs properties and their uses as valuable bioproducts.
[en] A microcomputer-based system for the continuous collection and analysis of data from a fermentor is described. The system was designed around commercially available hardware and interface and software packages written for microcomputers. Additional programmes were written in BASIC to allow the results to be printed in a specific format. The data read from the fermentor were automatically stored on a floppy disc and analysis on the data can be performed at our convenience. Such method for data collection is not limited to a bioreactor, however, since instruments that require continuous accurate reading, such as GLC, HPLC, etc., could be coupled to a microcomputer system. (author)