The Experts below are selected from a list of 21315 Experts worldwide ranked by ideXlab platform

Jui Shen Chiao - One of the best experts on this subject based on the ideXlab platform.

Xuefeng Lu - One of the best experts on this subject based on the ideXlab platform.

  • the potential of synechococcus elongatus utex 2973 for sugar feedstock production
    Applied Microbiology and Biotechnology, 2016
    Co-Authors: Kuo Song, Yajing Liang, Xuefeng Lu
    Abstract:

    It is important to obtain abundant sugar feedstocks economically and sustainably for bio-Fermentation Industry, especially for producing cheap biofuels and biochemicals. Besides plant biomass, photosynthetic cyanobacteria have also been considered to be potential microbe candidates for sustainable production of carbohydrate feedstocks. As the fastest growing cyanobacterium reported so far, Synechococcus elongatus UTEX 2973 (Syn2973) might have huge potential for bioproduction. In this study, we explored the potentials of this strain as photo-bioreactors for sucrose and glycogen production. Under nitrogen-replete condition, Syn2973 could accumulate glycogen with a rate of 0.75 g L−1 day−1 at the exponential phase and reach a glycogen content as high as 51 % of the dry cell weight (DCW) at the stationary phase. By introducing a sucrose transporter CscB, Syn2973 was endowed with an ability to secrete over 94 % sucrose out of cells under salt stress condition. The highest extracellular sucrose productivity reached 35.5 mg L−1 h−1 for the Syn2973 strain expressing cscB, which contained the similar amounts of intracellular glycogen with the wild type. Potassium chloride was firstly proved to induce sucrose accumulation as well as sodium chloride in Syn2973. By semi-continuous culturing, 8.7 g L−1 sucrose was produced by the cscB-expressing strain of Syn2973 in 21 days. These results support that Syn2973 is a promising candidate with great potential for production of sugars.

  • the potential of synechococcus elongatus utex 2973 for sugar feedstock production
    Applied Microbiology and Biotechnology, 2016
    Co-Authors: Kuo Song, Yajing Liang, Xuefeng Lu
    Abstract:

    It is important to obtain abundant sugar feedstocks economically and sustainably for bio-Fermentation Industry, especially for producing cheap biofuels and biochemicals. Besides plant biomass, photosynthetic cyanobacteria have also been considered to be potential microbe candidates for sustainable production of carbohydrate feedstocks. As the fastest growing cyanobacterium reported so far, Synechococcus elongatus UTEX 2973 (Syn2973) might have huge potential for bioproduction. In this study, we explored the potentials of this strain as photo-bioreactors for sucrose and glycogen production. Under nitrogen-replete condition, Syn2973 could accumulate glycogen with a rate of 0.75 g L−1 day−1 at the exponential phase and reach a glycogen content as high as 51 % of the dry cell weight (DCW) at the stationary phase. By introducing a sucrose transporter CscB, Syn2973 was endowed with an ability to secrete over 94 % sucrose out of cells under salt stress condition. The highest extracellular sucrose productivity reached 35.5 mg L−1 h−1 for the Syn2973 strain expressing cscB, which contained the similar amounts of intracellular glycogen with the wild type. Potassium chloride was firstly proved to induce sucrose accumulation as well as sodium chloride in Syn2973. By semi-continuous culturing, 8.7 g L−1 sucrose was produced by the cscB-expressing strain of Syn2973 in 21 days. These results support that Syn2973 is a promising candidate with great potential for production of sugars.

R.p. Ross - One of the best experts on this subject based on the ideXlab platform.

  • a multibacteriocin cheese starter system comprising nisin and lacticin 3147 in lactococcus lactis in combination with plantaricin from lactobacillus plantarum
    Applied and Environmental Microbiology, 2017
    Co-Authors: Susan Mills, Colin Hill, Wilco C Meijer, Carmel Griffin, Paula M Oconnor, L M Serrano, R.p. Ross
    Abstract:

    Functional starter cultures demonstrating superior technological and food safety properties are advantageous to the food Fermentation Industry. We evaluated the efficacies of single- and double-bacteriocin-producing starters of Lactococcus lactis capable of producing the class I bacteriocins nisin A and/or lacticin 3147 in terms of starter performance. Single producers were generated by mobilizing the conjugative bacteriophage resistance plasmid pMRC01, carrying lacticin genetic determinants, or the conjugative transposon Tn5276, carrying nisin genetic determinants, to the commercial starter L. lactis CSK2775. The effect of bacteriocin coproduction was examined by superimposing pMRC01 into the newly constructed nisin transconjugant. Transconjugants were improved with regard to antimicrobial activity and bacteriophage insensitivity compared to the recipient strain, and the double producer was immune to both bacteriocins. Bacteriocin production in the starter was stable, although the recipient strain proved to be a more efficient acidifier than transconjugant derivatives. Overall, combinations of class I bacteriocins (the double producer or a combination of single producers) proved to be as effective as individual bacteriocins for controlling Listeria innocua growth in laboratory-scale cheeses. However, using the double producer in combination with the class II bacteriocin producer Lactobacillus plantarum or using the lacticin producer with the class II producer proved to be most effective for reducing bacterial load. As emergence of bacteriocin tolerance was reduced 10-fold in the presence of nisin and lacticin, we suggest that the double producer in conjunction with the class II producer could serve as a protective culture providing a food-grade, multihurdle approach to control pathogenic growth in a variety of industrial applications.IMPORTANCE We generated a suite of single- and double-bacteriocin-producing starter cultures capable of generating the class I bacteriocin lacticin 3147 or nisin or both bacteriocins simultaneously via conjugation. The transconjugants exhibited improved bacteriophage resistance and antimicrobial activity. The single producers proved to be as effective as the double-bacteriocin producer at reducing Listeria numbers in laboratory-scale cheese. However, combining the double producer or the lacticin-producing starter with a class II bacteriocin producer, Lactobacillus plantarum LMG P-26358, proved to be most effective at reducing Listeria numbers and was significantly better than a combination of the three bacteriocin-producing strains, as the double producer is not inhibited by either of the class I bacteriocins. Since the simultaneous use of lacticin and nisin should reduce the emergence of bacteriocin-tolerant derivatives, this study suggests that a protective starter system produced by bacteriocin stacking is a worthwhile multihurdle approach for food safety applications.

Zhi Hao Sun - One of the best experts on this subject based on the ideXlab platform.

  • History of the acetone-butanol-ethanol Fermentation Industry in China: Development of continuous production technology
    Journal of Molecular Microbiology and Biotechnology, 2007
    Co-Authors: Jui Shen Chiao, Zhi Hao Sun
    Abstract:

    The acetone-butanol-ethanol (ABE) Fermentation Industry in China was started in the early 1950s in Shanghai and expanded rapidly thereafter. At its peak, there were about 30 plants all over the country and the total annual production of solvents reached 170,000 tons. This large enterprise was compelled to complete shutdown at the end of the 20th century due to the rapid increase of petrochemicals. The success of the ABE Industry in China had special features like the development of a continuous Fermentation technology. Its main strategic considerations were as follows: maintaining maximal growth and acid production phase, adoption of multiple stages in the solvent phase to allow gradual adaptation to increasing solvent, and the incorporation of stillage to offer enough nutrients to delay cell degeneration. Due to the tremendous national demand for solvents, China has begun a new round of ABE Fermentation research. It is expected that a new era in the ABE Industry is on the horizon.

Masayuki Machida - One of the best experts on this subject based on the ideXlab platform.

  • whole genome comparison of aspergillus flavus and a oryzae
    Medical Mycology, 2006
    Co-Authors: Gary A Payne, William C Nierman, Thomas E Cleveland, Deepak Bhatnagar, Ralph A Dean, Jennifer R Wortman, B L Pritchard, Doug Brown, Masayuki Machida
    Abstract:

    Aspergillus flavus is a plant and animal pathogen that also produces the potent carcinogen aflatoxin. Aspergillus oryzae is a closely related species that has been used for centuries in the food Fermentation Industry and is Generally Regarded As Safe (GRAS). Whole genome sequences for these two fungi are now complete, providing us with the opportunity to examine any genomic differences that may explain the different ecological niches of these two fungi, and perhaps to identify pathogenicity factors in A. flavus. These two fungi are very similar in genome size and number of predicted genes. The estimated genome size (36·8 Mb) and predicted number of genes (12 197) for A. flavus is similar to that of A. oryzae (36·7 Mb and 12 079, respectively). These two fungi have significantly larger genomes than Aspergillus nidulans (30·1) and Aspergillus fumigatus (29·4). The A. flavus and A. oryzae genomes are enriched in genes for secondary metabolism, but do not differ greatly from one another in the predicted numbe...

  • transcriptional analysis of genes for energy catabolism and hydrolytic enzymes in the filamentous fungus aspergillus oryzae using cdna microarrays and expressed sequence tags
    Applied Microbiology and Biotechnology, 2004
    Co-Authors: Hiroshi Maeda, Motoaki Sano, Yutaka Maruyama, Takeki Tanno, Takeshi Akao, Yoshiteru Totsuka, Misako Endo, Rumi Sakurada, Youhei Yamagata, Masayuki Machida
    Abstract:

    Aspergillus oryzae is a fungus used extensively in the Fermentation Industry. We constructed cDNA microarrays comprising 2,070 highly expressed cDNAs selected from the ∼6,000 non-redundant expressed sequence tags (ESTs) in the A. oryzae EST database (http://www.aist.go.jp/RIODB/ffdb/index.html). Using the cDNA microarrays, we analyzed the gene expression profiles of A. oryzae cells grown under the glucose-rich (AC) and glucose-depleted (AN) liquid culture conditions used during the construction of the EST database. The sets of genes identified by the cDNA microarray as highly expressed under each culture condition agreed well with the highly redundant ESTs obtained under the same conditions. In particular, transcription levels of most catabolic genes of the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle were higher under AC than AN conditions, suggesting that A. oryzae uses both EMP and TCA for glucose metabolism under AC conditions. We further studied the expression of genes encoding hydrolytic enzymes and enzymes involved in energy catabolism by using three industrial solid-phase biomass media, including wheat-bran. The wheat-bran culture gave the richest gene expression profile of hydrolytic enzymes and the lowest expression levels of catabolic genes (EMP, TCA) among the three media tested. The low expression levels of catabolic genes in the wheat-bran culture may release catabolite repression, consequently leading to the rich expression profiles of the hydrolytic enzymes.