E. E. Woodams

Apple pomace: A potential substrate for citric acid production by Aspergillus niger

SummaryApple pomace was used as a fsubstrate for citric acid production by five strains of Aspergillus niger. A. niger NRRL 567 produced the greatest amount of citric acid from apple pomace in the presence of 4% methanol. The yield was 88% based on the amount of sugar consumed.

Production of L(+)-lactic acid byRhizopus oryzae immobilized in calcium alginate gels

Lactic acid is produced commercially by the fermentation of carbohydrates with homofermentative lactic acid bacteria (Prescott and Dunn, 1959). Lockwood et al (1936) reported that selected strains ofRhizopus oryzae in surface culture converted glucose to a large amount of L(+)-lactic acid in the presence of calcium carbonate, and Prescott and Dunn (1959) reviewed the production of L(+)-lactic acid by molds.

Solid-state fermentation of grape pomace for ethanol production

SummaryGrape pomace was used as a substrate for the production of ethanol under solid-state fermentation conditions. The yield of ethanol amounted to greater than 80% of the theoretical, based on the fermentable sugar consumed.

Effect of substrate moisture content on fungal production of citric acid in a solid state fermentation system

SummaryUnder solid state fermentation conditions, the production of citric acid byAspergillusniger varied considerably with the initial moisture content of apple pomace. The stimulating effect of methanol on fungal production of citric acid decreased markedly as the substrate moisture decreased.

Enzymatic conversion of sucrose to kestose by fungal extracellular fructosyltransferase

SummaryAn extracellular fructosyltransferase (EC 2.4.1.9) fromAspergillus foetidus NRRL 337 was found capable of converting sucrose into a syrup containing more than 50% kestose. The production efficiencies ranged from 26 to 47%, depending oh sucrose concentration and the reaction time.

Fructosyltransferase activity of commercial enzyme preparations used in fruit juice processing

SummaryOf twenty-two commercial fungal enzyme preparations used in fruit juice processing examined, Pectinex Ultra SP-L, was found to possess the highest activity of fructosyltransferase (44.8 units/ml). The enzyme preparation converted sucrose into a high fructooliogosaccharide syrup containing 42.3 % kestose, 17.2% nystose, 10.6% sucrose, 27.8% glucose, and 2.1% fructose. The efficiency was 69% based the amount of sucrose consumed.

Enzymatic production of panose from maltose by glucosyltransferase from Aspergillus foetidus

Panose is a glucosyl-oligosaccharide that has been demonstrated to promote the growth of beneficial Bifidobacteria in the gut (Kitahata, 1989). It can also be used as an anti-cariogenic sweetener, because it prevents the production of waterinsoluble glucans by Streptococcus mutans and is not metabolized by many oral bacteria (Kuriki et al. 1992; Ooshima et al. 1988). Panose can be produced from maltose by the action of an intracellular glucosyltransferase from an Aureobasidium species (Hayashi et al. 1994). The objective of the present investigation was to determine the efficacy of an extracellular glucosyltransferase from a number of Aspergillus species as a biocatalyst for enzymatic production of panose from maltose.

Production of kestose from molasses with commercial juice processing enzyme preparation containing fructosyltransferase

Kestose and nystose are naturally occurring fmctooligosaccharides that have been shown to have beneficial health effects as a functional food component (Hidaka et al. 1988; Tomomatsu, 1994). They can be prepared from sucrose by the action of fungal fructosyltransferase (Hang and Woodams, 1995a), Hidaka et aI. 1988; Yun and Song, 1993). Commercial juice processing enzyme preparations derived from Aspergillus niger have been known to possess pectinolytic and cellulolytic enzymes (Rombouts and Pilnik, 1978). Of the 22 commercial enzyme preparations examined, Pectinex Ultra SP-L, has been found to contain the highest fmctosyltransferase activity (Hang and Woodams (1995b). Molasses is rich in sucrose and has been widely used as a substrate for a variety of industrial fermentation processes (Prescott and Dunn, 1959). The objective of this work was to determine the efficacy of Pectinex Ultra SP-L as a biocatalyst for the enzymatic production of kestose from beet molasses.