Browsing by Author "Gidamis, A. B."

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Comparative evaluation of different methods of extraction and purification used in technical enzyme production from microorganisms
(Tanzania J. Agric. Sc, 1998) Gidamis, A. B.; Nnko, A.; Shayo, N. B.; Chove, B. E.; Kroner, H. K.
A stlldy was conducted to compare the efficiency of two methods of microbial cell separation and enzyme purification using penicillin-G-acylase (PGA) from Escherichia coli. The efficiency of two methods of ceJ[ separation; centrifugation and cross flow filtration (CFF) were compared. The CFF method was found to have both higher separation efficiency and enzyme yield than centrifugation method. Centrifugation method gave a separation efficiency of 98.5% with enzyme yield of94 % whereas CFFmethod resulted in 100% separation efficiency and enzyme yield of98.8%. The Escherichia coli cells were disrupted by high pressure homogenization (HPH),and the disrupted cells were purified using two different techniques. Technique I was a combination of cross-flow-diafiltration (CFD) , ultrafiltration (UF) and heat/pH-shift treatments. This technique resulted in 47% enzyme yield with a purification factor of 12. Technique II which involved two extraction steps by' aqueous two - phase system (APS) coupled with UF resulted in 62 % enzyme yield with a pu;ificationfactor of 4. Technique I was therefore much better than techriique Il in purifying the enzyme. For higher enzyme yield, technique II would seem to be a better one than technique I.
Molecular improvement of food functional properties of Soybean glycinin by protein engineering
(Tanzania Journal of Agricultural Sciences, 1998) Gidamis, A. B.; Nnko, S. A.; Bunzo, M.; Utsumi, S.; Kito, M.
A study was made to elucidate the three dimensional structure of soybean glydnin which is one of the dominant storage proteins of soybean seeds. Previously, the twodisulphide bonds Cys12-Cys45 and Cys88-Cys298 in the proglydnin AlaBlb subunit were deleted andCys residues were replaced by Gly and Ser by Oligonucleotide-directed mutagenesis. The mutant proglycinins Gly12, and Ser88 showed to have better gelation and emulsifying properties. The mutant proglydnins were crystallised along with the normal proglycinin (AlaBlb -3) and subjected to X-ray structure analysis in an attempt to determine their structure-junction relationships. The crystals diffracted X-ray to a resollttion limit of 2.9 - 3.4A on stillphotographs and belongto the tetragonal system, space group P41 or P43 with cell dimensions of a = b·= 114.3 - 115.2A. and d;= 145.7 - 147.1A with 3 protomers per asymmetric unit. Further refinement data for the' crystals of normal prpglycinin were obtained by multiple isomorphous replacement and solvent flattening techniques. The tri1?ler dimensions of tlie normal proglydnin as determined at 6A were 93A by 93A with·the thickness of 36A.
The quality of water in small community supplies of Kingolwira village, Morogoro, Tanzania
(Tanzania Health Research, 2007) Shayo, N. B.; Chove, B. E.; Gidamis, A. B.; Ngoma, O. B.
Water quality is an important aspect in human health, as the majority of infectious diseases that cause morbidity and mortality in population are water related. The present study was undertaken to assess the quality of water in Kingolwira, Morogoro Rural District, Tanzania. Water was collected from different sites in the village and analysed for a period of six months. Physical, chemical and microbiological qualities of water were examined. The pH of the water ranged from 7.02 to 7.20 and the water temperature ranged from 25.70C to 27.00C. The total dissolved solids of the water samples ranged from 110 to 510 ppm. The water contained considerable levels of lead and copper ranging from 0.034 to 0.090 ppm and 0.022 to 0.030 ppm, respectively. Total water hardness ranged from 19.60 to 228.10 ppm as calcium carbonate. The total viable counts and faecal coliform counts ranged from 2.75x103 to 5.4 x 103 c.f.u/ml and 0.93 x102 to 2.1x102 counts/100ml, respectively. Overall, water supplies in the village were judged as of poor quality. Water is usually used for domestic purposes including cooking, drinking, washing and preparation of infant foods without any treatment. In conclusion therefore, water in Kingolwira village is of poor quality and needs to be treated before consumption. Theres is also a need for the rural population to be educated on hazards of using untreated water. In general, sanitary facilities in rural areas in Tanzania need to be improved in order to avoid health hazards.