Selecting lysine-excreting mutants of lactobacilli for use in food and feed enrichment

Effects of Cellulase and Lactic Acid Bacteria on Ensiling Performance and Bacterial Community of Caragana korshinskii Silage

The aim of this study was to evaluate the effects of cellulase (CE) and lactic acid bacteria (LAB) on Caragana korshinskii silage by analyzing the fermentation parameters, chemical composition, and bacterial community. The Caragana korshinskii was harvested at the fruiting period and treated with cellulase and LAB alone as a control treatment with no additive (CK). The ensiling performance and bacterial community were determined after 3, 7, 15, 30, and 60 days of fermentation process. Compared with the CK group, the pH, dry matter loss, and ammonia nitrogen content were significantly (p < 0.05) decreased in the LAB and CE treatments. Compared with the CK and LAB group, the contents of acid detergent fiber, neutral detergent fiber, and acid detergent lignin in the CE group decreased significantly (p < 0.05), and the water-soluble carbohydrates, acetic acid, and lactic acid concentrations increased significantly (p < 0.05). At the genus level of microorganisms, the addition of cellulase and LAB significantly reduced the microbial diversity. Compared with the CK group (78.05%), the relative abundance of Lactiplantibacillus in the CE group (90.19%) and LAB group (88.40%) significantly (p < 0.05) increased. The relative abundance of Pediococcus in the CE group (3.66%) and LAB group (2.14%) was significantly (p < 0.05) lower than that in the CK group (14.73%). Predicted functional profiling of 16S rRNA genes revealed that the addition of cellulase and LAB increased the pyruvate metabolic pathway during Caragana korshinskii silage, thereby increasing the accumulation of lactic acid concentration. The addition of cellulase expressed a better advantage in the biosynthetic capacity of lysine. In summary, the addition of cellulase and LAB could adjust the bacterial community to improve the silage quality of Caragana korshinskii, and the addition of cellulase exhibited better results than the LAB additives.

Striga Biocontrol on a Toothpick: A Readily Deployable and Inexpensive Method for Smallholder Farmers

Striga hermonthica (witchweed) is a parasitic weed that attacks and significantly reduces the yields of maize, sorghum, millet, and sugarcane throughout sub-Saharan Africa. Low cost management methods such as hand weeding, short crop rotations, trap cropping, or conventional biocontrol have not been effective. Likewise, Striga-tolerant or herbicide-resistant maize cultivars are higher yielding, but are often beyond the economic means of sustenance farmers. The fungal pathogen, Fusarium oxysporum f.sp. strigae, has been the object of numerous studies to develop Striga biocontrol. Under experimental conditions this pathogen can reduce the incidence of Striga infestation but field use is not extensive, perhaps because it has not been sufficiently effective in restoring crop yield and reducing the soil Striga seed bank. Here we brought together Kenyan and US crop scientists with smallholder farmers to develop and validate an effective biocontrol strategy for management of Striga on smallholder farms. Key components of this research project were the following: (1) Development of a two-step method of fungal delivery, including laboratory coating of primary inoculum on toothpicks, followed by on-farm production of secondary field inoculum in boiled rice enabling delivery of vigorous, fresh inoculum directly to the seedbed; (2) Training of smallholder farmers (85% women), to produce the biocontrol agent and incorporate it into their maize plantings in Striga-infested soils and collect agronomic data. The field tests expanded from 30 smallholder farmers to a two-season, 500-farmer plot trial including paired plus and minus biocontrol plots with fertilizer and hybrid seed in both plots and; (3) Concerted selection of variants of the pathogen identified for enhanced virulence, as has been demonstrated in other host parasite systems were employed here on Striga via pathogen excretion of the amino acids L-leucine and L-tyrosine that are toxic to Striga but innocuous to maize. This overall strategy resulted in an average of >50% increased maize yield in the March to June rains season and >40% in the September to December rains season. Integration of this enhanced plant pathogen to Striga management in maize can significantly increase the maize yield of smallholder farmers in Kenya.

Cereal based functional food of Indian subcontinent: a review

Due to constant health awareness and readily available information on usefulness of different diet and their direct link with health, the demand of functional food is increasing day by day. The concept of functional foods includes foods or food ingredients that exert a beneficial effect on host health and/or reduce the risk of chronic disease beyond basic nutritional functions. Increasing awareness of consumer health and interest in functional foods to achieve a healthy lifestyle has resulted in the need for food products with versatile health-benefiting properties. Cereal- and cereal component-based food products offer opportunities to include probiotics, prebiotics, and fibers in the human diet. Various growth studies using probiotic Lactic acid bacteria on cereal-based substrates and utilization of whole grain or components as high-fiber foods in developing novel food products lend support to the idea that cereal-based media may well be good probiotic carriers. It is essential that science and traditional knowledge should go together to find mutually beneficial results. In the Indian subcontinent, making use of fermented food and beverages using local food crops and other biological resources are very common. But the nature of the products and the base material vary from region to region.

Elevating optimal human nutrition to a central goal of plant breeding and production of plant-based foods

High-yielding cereals and other staples have produced adequate calories to ward off starvation for much of the world over several decades. However, deficiencies in certain amino acids, minerals, vitamins and fatty acids in staple crops, and animal diets derived from them, have aggravated the problem of malnutrition and the increasing incidence of certain chronic diseases in nominally well-nourished people (the so-called diseases of civilization). Enhanced global nutrition has great potential to reduce acute and chronic disease, the need for health care, the cost of health care, and to increase educational attainment, economic productivity and the quality of life. However, nutrition is currently not an important driver of most plant breeding efforts, and there are only a few well-known efforts to breed crops that are adapted to the needs of optimal human nutrition. Technological tools are available to greatly enhance the nutritional value of our staple crops. However, enhanced nutrition in major crops might only be achieved if nutritional traits are introduced in tandem with important agronomic yield drivers, such as resistance to emerging pests or diseases, to drought and salinity, to herbicides, parasitic plants, frost or heat. In this way we might circumvent a natural tendency for high yield and low production cost to effectively select against the best human nutrition. Here we discuss the need and means for agriculture, food processing, food transport, sociology, nutrition and medicine to be integrated into new approaches to food production with optimal human nutrition as a principle goal.

The effects of processing methods on the levels of lysine, methionine and the general acceptability of ogi processed using starter cultures

Batches of ogi were produced from maize flour slurry, dehulled maize grains and whole maize grains using Saccharomyces cerevisiae and Lactobacillus brevis as starter cultures. Fermentation over time showed that dehulled maize grains inoculated with the starter cultures and processed whole maize grains requiring steeping led to higher acid production than fermentation with dry-milled maize slurry. Ogi from dehulled maize grains inoculated with starter cultures showed the highest levels of lysine and methionine. Steeping grains encouraged a stronger ogi aroma than fermentation of maize flour slurry alone. Lactobacillus brevis contributed most to the taste of ogi. Fermentation with starter cultures showed good prospects for improving the lysine and methionine levels of ogi.

Evaluation of lysine and methionine production in some Lactobacilli and yeasts from ogi

Lysine and methionine producing cultures of Lactobacillus and yeasts in batch fermentation of ogi were selected by growth in the presence of the analogues, S-2-aminoethyl]-L-cysteine (thialysine) and ethionine respectively. The study shows that 42.5% of the Lactobacillus and 83.3% of the yeast isolates tested were capable of lysine production while 25.0% of the Lactobacillus and 87.8% of the yeast isolates produced methionine. The lysine and methionine yields of Lactobacillus were significantly (P <0.01) higher than that of yeasts. The majority of the yeast isolates excreted most of the lysine and methionine produced. More lysine was produced than methionine in all tested isolates.