Lactic acid production by simultaneous saccharification and fermentation of alfalfa fiber.

Lactic acid was produced by simultaneous saccharification and fermentation (SSF) of liquid hot water (LHW)-pretreated and non-LHW-pretreated alfalfa fibers. The Lactobacillus plantarum and L. delbrueckii strains produced 0.464 and 0.354 g of lactic acid per g of dry matter of alfalfa fiber, respectively, by non-LHW pretreatment. L. xylosus and L. pentoaceticus produced lower yields of lactic acid from the same amount of alfalfa fiber, however, their acetic acid production was higher. These Lactobacillus strains did not require any additional nutrients during SSF of non-LHW-pretreated alfalfa fiber. After LHW pretreatment, the "raffinate" cellulosic fraction of alfalfa required additional nutrients for lactic acid production by SSF. Both L. plantarum and L. delbrueckii produced 0.606 and 0.59 g of lactic acid per g of dry matter of fiber, respectively. However, the "extract" soluble hemicellulosic fraction of alfalfa produced 0.38 to 0.62 g of lactic acid per g of dry matter extract during SSF and did not require nutrient supplementation. These results suggest that during the LHW pretreatment, alfalfa fiber nutrients are lost in cellulosic fractions but retained in hemicellulosic extract fractions.

An overview of a feasibility study for the production of industrial enzymes in transgenic alfalfa.

The overall aims of the research are to develop genetically engineered alfalfa producing high levels of industrially important enzymes and to develop rapid methods for extracting and purifying these enzymes from alfalfa juice. Using a reporter gene beta-glucuronidase (GUS) as a model system, we were able to demonstrate production of a foreign protein in alfalfa and gain valuable insight into the molecular approaches required for the expression and accumulation of foreign proteins in leaf tissue. GUS activity varied among individual transformants, and GUS was expressed in all plant tissues. GUS activity was shown to segregate in sexual progeny. There was no correlation between copy number of the GUS gene and activity. We have recently demonstrated the production of Mn-dependent lignin peroxidase and alpha-amylase in transgenic alfalfa. Concurrent research in the agricultural engineering aspects of this feasibility study focused on extraction strategies for the recovery of alfalfa juice, and on an evaluation of methods for processing and concentrating the juice. Thus, we are in a position to use plants expressing enzymes that have current or potential industrial importance to complete a feasibility study, and determine whether we can indeed economically recover target enzymes from field-grown transgenic alfalfa plants. The technology developed for these enzymes can be used to extract other value-added products from plants in the future.

Critical vitamin supplementation of broiler diets high in alfalfa juice protein.

Three trials were conducted to identify the critical vitamins in the diets of broiler-strain chicks fed alfalfa juice protein concentrate (AJPC) corn-soy diets from 0 to 3 wk of age. Vitamin supplements were added to AJPC diets. Diets were formulated to contain, parts 30/121, 40/128, 50/135, and 60/142 parts AJPC/parts total diet. Parts were used to permit usage of wet materials and still maintain about 90% dry matter. All diets were formulated to contain 20% crude protein, .93% total sulfur-containing amino acids, and 2,940 kcal metabolizable energy/kg diet. Propionic acid was added at .2% to all diets. Feeds were refrigerated (7 C) and fed out daily. The addition of choline, riboflavin, vitamin B12, vitamin A or E, folic acid, or biotin did not increase weight gains. Addition of 3 mg/kg vitamin B6 completely overcame the growth depression caused by the 50-parts AJPC diet and significant (P less than .05) growth increases (13 to 29%) were achieved with vitamin-B6 supplementation to the 60-parts AJPC diet. Depressed immune responses were completely prevented by the addition of 3 mg/kg of vitamin B6. The significant (P less than .05) increases in leg deformities observed in birds fed the 60-parts AJPC diet were also brought back to more typical values in birds fed the diet supplemented with 3 mg/kg vitamin B6. Vitamin K supplementation (.53 mg/kg) to the 60-parts AJPC diet resulted in significant decreases from 15 min in blood clotting times to 3 to 5 min.(ABSTRACT TRUNCATED AT 250 WORDS)