Journal of Applied Biotechnology

1-12

Authors: Melkhianus H. Pentury, Happy Nursyam, Nuddin Harahap, Soemarno

Hipocotyl Bruguiera gymnorrhiza High carbohydrate, but in Indonesia has not been exploited and developed, this is an alternative hypocotyl development for manufacturing starch as food ingredients industry. In addition to looking for new sources of starch for the modern food industry, also need to know the functional properties of starch. It aims to facilitate the diversification of the use of starch hypocotyl Bruguiera gymnorrhiza in various food industries. The purpose of this study was to determine the effect of sodium bisulfite solution concentration and temperature of heating and the interaction against best quality starch. In this study, the concentration of sodium bisulfite and heating temperature as a variable is changed, while the fixed variables are time and temperature of drying. The study was conducted using a completely randomized factorial design with three replications with 2 factors that NaHSO3 concentration of 0.10%, 0.20%, 0.25% and 0.40% and heating temperature 40 °C, 50 °C and 6 °C. Verse data processing using SPSS 16.0. Test parameters namely amylose content, solubility, viscosity, reducing sugar and starch content. The best treatment was determined using the method of De Garmo. These results indicate that treatment factors temperature and concentration on the extraction of starch hipocotyl Bruguiera gymnorrhiza significant effect (P < 0.01) of the amylose content, starch content, viscosity, solubility and reduced sugar. Interaction heating temperature and concentration also had a significant effect on amylose content, starch content, viscosity, solubility and reduced sugar. Treatment with a heating temperature of 60 °C and the concentration of 0.25% for 5 minutes is the best treatment result was 19,58 % amylose content, starch content of 65.00%, 520.33 cP viscosity, solubility and reducing sugar 91.99% 0.27%.

32-42

Authors: Laura Osorno, Nelson Walter Osorio

Inorganic Phosphate (Pi) is an essential nutrient for plant growth and development, however that most soils have in low availability. To overcome this problem it is necessary to apply high amounts of Pi fertilizers, however this is inefficient and costly. Recently, there is increasing interest in the use of rock phosphate (RP) and microorganisms capable of increasing its agronomic effectiveness as crop fertilizer. However, it is unclear the impact that some critical nutrients such as carbon (C) and nitrogen (N) may have on the effectiveness of the microbial RP dissolution. The aim of this study was to evaluate the effect of C and N source and concentration on the RP dissolution by the fungus Mortierella sp. under in vitro conditions. The results indicate that the efficiency to dissolve RP was significantly higher with glucose, followed by arabinose; other sources were ineffective (fructose, sucrose, maltose, cellulose and molasses). On the other hand, NH4Cl was significantly the most effective N source, followed by NH4NO3. By contrast, KNO3 was ineffective to promote RP dissolution. The best concentration of glucose was 10 g L-1, while for NH4Cl it was 1 g L-1. These findings show that by varying nutrient supply, the RP dissolution reactions can be significantly enhanced.

65-74

Authors: Ashok Kumar Chauhan, Surya Pratap Singh, Ashwani Kumar

Biodesulfurization of organosulfur compounds is mediated by activity of the enzymes DszA, DszB and DszC. Here, we report the nucleotide sequence of an 11.5 kb region, containing the dszABC genes along with 3.3 kb upstream and 4.5 kb down-stream region, from a desulfurizing strain Gordonia sp IITR100. The genes are organized together as dszABC in an operon, and their nucleotide sequence is > 99% identical to those from the Gordonia strains IB, RIPI90A & CYKS2. The sequence upstream to dszA, is identical to the reported -1 to -1800 bp from the corresponding region of CYKS2, but presence of two transposase genes was identified in the remaining 2.7 kb region. Sequence of the region downstream to dszC was found to be distinct from all the desulfurizing organisms. BLAST analysis suggested that the cloned 11.5 kb region was possibly formed by crossover between the genomes a Mycobacterium and a Gordonia strain at a site 206 bp downstream to dszC. The results have bearing on understanding the organization and horizontal transfer of the desulfurization genes.