No description available.

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Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 131-148).

Thesis (M. Phil.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 100-118).

A chemically defined medium containing no amino acids supported cellular growth of A. suboxydans NCIB 9108. The effectiveness of selected carbon sources for the growth of the organism in a carbohydrate/salts medium was investigated. Growth was, in general, stimulated by the addition of vitamins to a sorbitol/salts medium. The role of yeast extract as a supplier of growth factors is described. The product of sorbitol oxidation by whole growing cells of A. suboxydans was found to be sorbose. G.L.C. analysis showed that sorbitol was completely oxidised to sorbose. Induction of sorbitol dehydrogenase activity by A. suboxydans in the presence of various carbon sources was investigated. Production of sorbitol dehydrogenase during the growth of A. suboxydans on all the carbon sources investigated was found to be maximal in the late log phase. Sorbitol dehydrogenase from A. suboxydans was purified by ammonium sulphate fractionation, chromatography on DEAE-Cellulose and bioaffinity chromatography on 5' AMP-Sepharose 4B. The purification of the partially purified enzyme increased 17 fold (after DEAE-Cellulose chromatography) and 80 fold (after 5' AMP-Sepharose 4B bioaffinity chromatography) compared with the crude extract. The enzyme has a pH optimum in the range of 6.5 - 7.0 with a maximum velocity of 5.35 U. mg-1. The Km was found to be 176 mM for fructose and 0.028 mM m for NADH. Inhibition studies involving sorbitol, mannitol, sorbose, nicotinamide, salicylic acid, P-chloromercuribenzoate and o-iodosobenzoate demonstrated competitive inhibition with all inhibitors studied except sorbose which exhibited uncompetitive inhibition. The values were found to be 19 mM, 600 mM, 13 mM, 5 mM, 10.4 mM, 1.3 mM and 3.6 mM respectively.

Orientador: Raquel Marques Braga / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-07-21T19:21:44Z (GMT). No. of bitstreams: 1 Kato_Lucilia_M.pdf: 5410191 bytes, checksum: b7e9a09bd7f43f96d949c6a072a7ce7e (MD5) Previous issue date: 1996 / Mestrado

A key economic pest of cotton in the mid-south is the tarnished plant bug (TPB), Lygus lineolaris (Hemiptera: Miridae). It is believed that early season crops like corn play a major role in building up TPB populations which then move to nearby cotton fields. The objective of this research was to determine the movement dynamics of TPB at the interface of these crops. Our 2009 data indicate TPB movement from corn into cotton occurred when corn was maturing from silk stage to milk. However, tasseling corn is more attractive compared to pre-squaring cotton to TPB. A supporting study evaluated the retention time of protein markers under simulated midsouth summer conditions. We measured the impact of adding sorbitol to an egg protein solution on retention time of the protein on TPB acquisition. We found that sorbitol decreased acquisition time and raised the detection values of proteins in the absence of rain.

No description available.

No description available.