N-ethylmaleimide (NEM) modification of a lactose permease mutant containing a single-Cys in place of Ala-122 (helix IV) abolishes active lactose transport. Moreover, lactose, melibiose, and beta,d-galactopyranosyl 1-thio-beta,D-galactopyranoside protect against NEM inactivation of lactose transport and/or alkylation of Cys-122 by [(14)C]NEM. Remarkably, however, D-galactose transport is relativ...

Lactose intolerance is observed in black and Mexican-American children by age 3 years, and it probably occurs in other non-northern European ethnic groups at a similar age. However, intolerance to the consumption of 250 ml of milk apparently is rarely seen in preadolescents. Current research on the response of adolescents to hydrolyzed lactose milk suggests that the symptoms observed in lactose...

Cheese whey, the main dairy by-product, is increasingly recognized as a source of many bioactive valuable compounds. Nevertheless, the most abundant component in whey is lactose (ca. 5% w/v), which represents a significant environmental problem. Due to the large lactose surplus generated, its conversion to bio-ethanol has long been considered as a possible solution for whey bioremediation. In t...

Many marine bacteria secrete exopolysaccharides (EPSs) that have important ecological and physiological functions. Numerous nutritional and environmental factors influence bacterial EPS production. However, the regulatory mechanisms of EPS production are poorly understood. The deep-sea Bacteroidetes bacterium Zunongwangia profunda SM-A87 can produce high quantities of EPS, and its EPS productio...

BACKGROUND Relationships between inflammatory bowel disease and lactose containing foods remain controversial and poorly defined regarding symptoms, nutritional outcomes, and epidemiologic associations for lactose maldigestion. METHODS A literature review was performed using Pub Med, Cochrane library and individual references, to extract data on lactose maldigestion prevalence in inflammatory...

One hundred and fourteen strains of non-lactose fermenters and 127 lactose fermenters on MacConkey's agar have been compared in the 5% and 1% lactose tests and in beta-galactosidase production, using ortho-nitro-phenyl-beta-D-galactopyranoside (O.N.P.G.) as a test substance. The superiority of the O.N.P.G. test in the number of positive results and its rapidity is shown. In general, late or non...

The growth rate and feed efficiency of pigs fed a diet containing 10% dried whey and 20% alfalfa was less than with either treatment alone, suggesting a possible antagonism between alfalfa and whey. A digestibility trial with rats indicated that feeding lactose, a major constituent of whey, reduced the digestibility of alfalfa fiber and purified cellulose. In another rat experiment, the feeding...

BACKGROUND There is evidence from animal studies that lactose has a beneficial effect on intestinal calcium absorption. However, data concerning the effect of lactose on calcium absorption in lactose-tolerant adults are inconclusive. OBJECTIVE Our objective was to investigate the effect of lactose on calcium bioavailability in humans by the use of a stable-strontium test under controlled meta...

Most people are born with the ability to digest lactose. Approximately 75% of the general population loses this ability, to some extent, going into adulthood (adult hypolactasia), while others retain such ability. The aim of the present study was to determine the prevalence of lactose intolerance, and its correlation with gastrointestinal symptoms, in primary school children aged 6-12 years in ...

Lactose is the only soluble and economically feasible carbon source for the production of cellulases or heterologous proteins regulated by cellulase expression signals by Hypocrea jecorina (Trichoderma reesei). We investigated the role of the major -galactosidase of H. jecorina in lactose metabolism and cellulase induction. A genomic copy of the bga1 gene was cloned, and this copy encodes a 1,0...