Metabolomic characterization of malolactic fermentation and fermentative behaviors of wine yeasts in grape wine.

Wine contains a number of metabolites that are produced during alcoholic and malolactic fermentations (MLF) or aging, which are important compounds for determining wine quality. This study investigated changes in metabolites in wines to characterize malolactic fermentation (MLF) and to assess fermentative behaviors of wine yeast strains using (1)H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistics. Principal component analysis (PCA) showed clear differentiation between non- and induced-malolactic fermented wines by wine lactic acid bacteria (LAB) and between wines fermented with various wine yeast strains. Metabolites such as glycerol, lactate, 2,3-butanediol, succinate, leucine, isoleucine, alanine, valine, proline, choline, gamma-aminobutyric acid (GABA), and polyphenols contributed to the differentiations. Decreased levels of malate and citrate along with increased levels of lactate were the metabolites most responsible for the differentiation of induced-MLF wines from non-MLF wines. In particular, high succinate levels provided evidence of an inhibitory effect of Saccharomyces bayanus against spontaneous MLF. Furthermore, dependence of metabolites on wine yeast strains was observed, demonstrating their different fermentative behaviors. This study demonstrates that wine fermentation by yeast and LAB can be characterized through global and multivariate statistical analysis of (1)H NMR spectral data.

Metabolomic studies on geographical grapes and their wines using 1H NMR analysis coupled with multivariate statistics.

Environmental vineyard conditions can affect the chemical composition or metabolites of grapes and their wines. Grapes grown in three different regions of South Korea were collected and separated into pulp, skin, and seed. The grapes were also vinified after crushing. (1)H NMR spectroscopy with pattern recognition (PR) methods was used to investigate the metabolic differences in pulp, skin, seed, and wines from the different regions. Discriminatory compounds among the grapes were Na, Ca, K, malate, citrate, threonine, alanine, proline, and trigonelline according to PR methods of principal component analysis (PCA) or partial least-squares discriminant analysis (PLS-DA). Grapes grown in regions with high sun exposure and low rainfall showed higher levels of sugar, proline, Na, and Ca together with lower levels of malate, citrate, alanine, threonine, and trigonelline than those grown in regions with relatively low sun exposure and high rainfall. Environmental effects were also observed in the complementary wines. This study demonstrates that (1)H NMR-based metabolomics coupled with multivariate statistical data sets can be useful for determining grape and wine quality.

New method development for nanoparticle extraction of water-soluble beta-(1-->3)-D-glucan from edible mushrooms, Sparassis crispa and Phellinus linteus.

Sparassis crispa and Phellinus linteus are edible/medicinal mushrooms that have remarkably high contents of beta-(1-->3)-D-glucan, which acts as a biological response modifier, but difficulty in cultivating the fruiting bodies and extraction of beta-D-glucan have restricted detailed studies. Therefore, a novel process for nanoparticle extraction of Sparan, the beta-D-glucan from Sparassis crispa, and Phellin, the beta-D-glucan from Phellinus linteus, has been investigated using insoluble tungsten carbide as a model for nanoknife technology. This is the first report showing that the nanoknife method results in high yields of Sparan (70.2%) and Phellin (65.2%) with an average particle size of 150 and 390 nm, respectively. The extracted Sparan with beta-(1-->3) linkages showed a remarkably high water solubility of 90% even after 10 min of incubation at room temperature. Therefore, it is likely that this nanoknife method could be used to produce beta-D-glucan for food, cosmetic, and pharmaceutical industries.

(1)H NMR-based metabolomic approach for understanding the fermentation behaviors of wine yeast strains.

(1)H NMR spectroscopy coupled with multivariate statistical analysis was used for the first time to investigate metabolic changes in musts during alcoholic fermentation and wines during aging. Three Saccharomyces cerevisiae yeast strains (RC-212, KIV-1116, and KUBY-501) were also evaluated for their impacts on the metabolic changes in must and wine. Pattern recognition (PR) methods, including PCA, PLS-DA, and OPLS-DA scores plots, showed clear differences for metabolites among musts or wines for each fermentation stage up to 6 months. Metabolites responsible for the differentiation were identified as valine, 2,3-butanediol (2,3-BD), pyruvate, succinate, proline, citrate, glycerol, malate, tartarate, glucose, N-methylnicotinic acid (NMNA), and polyphenol compounds. PCA scores plots showed continuous movements away from days 1 to 8 in all musts for all yeast strains, indicating continuous and active fermentation. During alcoholic fermentation, the highest levels of 2,3-BD, succinate, and glycerol were found in musts with the KIV-1116 strain, which showed the fastest fermentation or highest fermentative activity of the three strains, whereas the KUBY-501 strain showed the slowest fermentative activity. This study highlights the applicability of NMR-based metabolomics for monitoring wine fermentation and evaluating the fermentative characteristics of yeast strains.

1H nuclear magnetic resonance-based metabolomic characterization of wines by grape varieties and production areas.

(1)H NMR spectroscopy was used to investigate the metabolic differences in wines produced from different grape varieties and different regions. A significant separation among wines from Campbell Early, Cabernet Sauvignon, and Shiraz grapes was observed using principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The metabolites contributing to the separation were assigned to be 2,3-butanediol, lactate, acetate, proline, succinate, malate, glycerol, tartarate, glucose, and phenolic compounds by PCA and PLS-DA loading plots. Wines produced from Cabernet Sauvignon grapes harvested in the continental areas of Australia, France, and California were also separated. PLS-DA loading plots revealed that the level of proline in Californian Cabernet Sauvignon wines was higher than that in Australian and French Cabernet Sauvignon, Australian Shiraz, and Korean Campbell Early wines, showing that the chemical composition of the grape berries varies with the variety and growing area. This study highlights the applicability of NMR-based metabolomics with multivariate statistical data sets in determining wine quality and product origin.

Detection and recovery of hydrolytic enzymes from spent compost of four mushroom species.

To evaluate the potential of using the enzymes from spent mushroom compost (SMC) as an industrial enzyme, the production of alpha-amylase, cellulase, beta-glucosidase, laccase, and xylanase was determined from the SMC of four edible mushroom species (Pleurotus ostreatus, Lentinula edodes, Flammulina velutipes and Hericium erinaceum). Among the tested SMC, the SMC of L. edodes showed the highest enzyme activity in alpha-amylase (229 nkat/g), cellulase (759 nkat/g) and beta-glucosidase (767 nkat/g) in 0.5% Triton X-100, and that of P. ostreatus showed the highest activity in laccase (1452 nkat/g) in phosphate-buffered 0.2% Triton X-100. The highest xylanase activity (119 nkat/g) was found in the SMC of F. velutipes.

Comparative study of mycelial growth and basidiomata formation in seven different species of the edible mushroom genus Hericium.

The potential of using several agricultural by-products as supplements of sawdust substrate for the production of edible mushroom Hericium was evaluated using seven Hericium species. All the tested supplements (rice bran, wheat bran, barley bran, Chinese cabbage, egg shell, and soybean powder) were found to be suitable for the mycelial growth of all the tested species. In mycelial growth, soybean powder was the best supplement for Hericium americanum, Hericium coralloides, and Hericium erinaceum while barley bran was the best for Hericium alpestre, Hericium laciniatum, and Hericium erinaceus. For Hericium abietis, rice bran and Chinese cabbage was the best. The possibility of mushroom production on oak sawdust substrate with 20% rice bran supplement was demonstrated with H. coralloides, H. americanum, H. erinaceus, and H. erinaceum which showed 26-70% biological efficiency. Our results also showed that strain selection is important to improve biological efficiency and mushroom yield in Hericium cultivation.

Systemic movement of a movement-deficient strain of Cucumber mosaic virus in zucchini squash is facilitated by a cucurbit-infecting potyvirus.

Zucchini squash (Cucurbita pepo) is a systemic host for most strains of the cucumovirus Cucumber mosaic virus (CMV), although the long-distance movement of the M strain of CMV (M-CMV) is inhibited in some cultivars. However, co-infection of zucchini plants with M-CMV and the potyvirus Zucchini yellow mosaic virus strain A (ZYMV-A) allowed M-CMV to move systemically, as demonstrated by tissue-print analysis. These doubly infected plants exhibited severe synergism in pathology. Infection of zucchini squash by M-CMV and an attenuated strain of ZYMV (ZYMV-AG) showed a milder synergy in pathology, in which ZYMV-AG also facilitated the long-distance movement of M-CMV similar to that promoted by ZYMV-A. Variation in the extent of synergy in pathology by the two strains of ZYMV did not correlate with differences in levels of accumulation of either virus. Thus, the extent of synergy in pathology is at least in part independent of the resistance-neutralizing function of the potyvirus.

Generation of infectious cDNA clones of a Korean strain of tomato aspermy virus.

Infectious full-length cDNA clones of the Korean strain of tomato aspermy cucumovirus (KC-TAV) were constructed using a long-template reverse transcription-polymerase chain reaction. The in vitro RNA transcripts, which were produced using T7 RNA polymerase from full-length cDNAs, could systemically infect the Nicotiana tabacum cv. Xanti-nc plants and induce systemic symptoms on the upper leaves that are similar to the wildtype KC-TAV. The complete nucleotide sequences of genomic RNAs of KC-TAV were determined from the infectious full-length cDNA clones. RNA1 and RNA2 of KC-TAV contain 3412 nucleotides and 3074 nucleotides, respectively. RNA3 of KC-TAV, 2222 nucleotides long, encodes the 3a protein and coat protein (CP) that are separated by 295 nucleotides intergenic region. The overall sequence analysis of the whole genome of KC-TAV revealed a strong homology (99%) to the genome of the V-TAV strain, the only strain whose entire genomic nucleotide sequence was available in the database, and an overall 60% homology to those of other cucumber mosaic virus and peanut stunt virus strains. A sequence comparison analysis of the deduced amino acid sequences of cDNAs of KC-TAV RNA 1, 2, and 3 indicates that there is no genetic diversity in the TAV population, although the virus exists in different geographical distributions.