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351.
A 16.5-kb BamHI fragment of the Cellvibrio mixtus chromosome was found to direct carboxymethylcellulase, xylanase, and avicel hydrolysis. Two closely linked genes were subcloned
from this insert. The gene, cmcI, was cloned as a 2.7-kb fragment and expressed in Escherichia coli. It encoded an enzyme of approximately 74 kDa which degraded carboxymethylcellulose and xylan but did not attack the microcrystalline
cellulose substrate avicel. A second cellulase capable of degrading avicel, encoded by exoI, was found 5.5 kb downstream of cmcI. Two translation products of 53.7 kDa and 51.5 kDa were produced in E. coli strains expressing exoI. Northern analysis of total mRNA of C. mixtus grown on avicel, with a probe generated from cmcI, showed that cmcI and exoI were not cotranscribed in an operon.
Received: 7 December 1995 / Accepted: 3 January 1996 相似文献
352.
353.
Effects of Fecal Microbial Transplantation on Microbiome and Immunity in Simian Immunodeficiency Virus-Infected Macaques 总被引:1,自引:0,他引:1
354.
Ricardo Bermejo Maria Galindo-Ponce Nessa Golden Charlene Linderhoff Svenja Heesch Ignacio Hernández Liam Morrison 《Journal of phycology》2023,59(1):167-178
The generalized use of molecular identification tools indicated that multispecific green tides are more common than previously thought. Temporal successions between bloom-forming species on a seasonal basis were also revealed in different cold temperate estuaries, suggesting a key role of photoperiod and temperature controlling bloom development and composition. According to the Intergovernmental Panel on Climate Change, water temperatures are predicted to increase around 4°C by 2100 in Ireland, especially during late spring coinciding with early green tide development. Considering current and predicted temperatures, and photoperiods during bloom development, different eco-physiological experiments were developed. These experiments indicated that the growth of Ulva lacinulata was controlled by temperature, while U. compressa was unresponsive to the photoperiod and temperatures assayed. Considering a scenario of global warming for Irish waters, an earlier development of bloom is expected in the case of U. lacinulata. This could have significant consequences for biomass balance in Irish estuaries and the maximum accumulated biomass during peak bloom. The observed seasonal patterns and experiments also indicated that U. compressa may facilitate U. lacinulata development. When both species were co-cultivated, the culture performance showed intermediate responses to experimental treatments in comparison with monospecific cultures of both species. 相似文献
355.
Giles C. Shih Charlene M. Kahler John S. Swartley M. Mahbubur Rahman Jack Coleman Russell W. Carlson & David S. Stephens 《Molecular microbiology》1999,32(5):942-952
Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are critical phospholipid intermediates in the biosynthesis of cell membranes. In Escherichia coli, LPA acyltransferase (1-acyl-sn-glycerol-3-phosphate acyltransferase; EC 2.3.1.51) catalyses the transfer of an acyl chain from either acyl-coenzyme A or acyl-acyl carrier protein onto LPA to produce PA. While E. coli possesses one essential LPA acyltransferase (PlsC), Neisseria meningitidis possesses at least two LPA acyltransferases. This study describes the identification and characterization of nlaB (neisserial LPA acyltransferase B), the second LPA acyltransferase identified in N. meningitidis. The gene was located downstream of the Tn916 insertion in N. meningitidis mutant 469 and differed in nucleotide and predicted amino acid sequence from the previously characterized neisserial LPA acyltransferase homologue nlaA. NlaB has specific LPA acyltransferase activity, as demonstrated by complementation of an E. coli plsC(Ts) mutant in trans, by decreased levels of LPA acyltransferase activity in nlaB mutants and by lack of complementation of E. coli plsB26,X50, a mutant defective in the first acyltransferase step in phospholipid biosynthesis. Meningococcal nlaA mutants accumulated LPA and demonstrated alterations in membrane phospholipid composition, yet retained LPA acyltransferase activity. In contrast, meningococcal nlaB mutants exhibited decreased LPA acyltransferase activity, but did not accumulate LPA or display any other observable membrane changes. We propose that N. meningitidis possesses at least two LPA acyltransferases to provide for the production of a greater diversity of membrane phospholipids. 相似文献
356.
Yvonne Jackson William H. Dietz Charlene Sanders Lloyd J. Kolbe John J. Whyte Howell Wechsler Bruce S. Schneider Laura A. McNally Jean Charles-Azure Martina Vogel-Taylor Pamela Starke-Reed Van S. Hubbard Wendy L. Johnson-Taylor Ph.D. MPH R.D. Richard P. Troiano Karen Donato Susan Yanovski Robert J. Kuczmarski Lynne Haverkos Kathryn McMurry Randolph F. Wykoff Violet Woo Allan S. Noonan Jonelle Rowe Kathy McCarty Christine B. Spain 《Obesity (Silver Spring, Md.)》2002,10(12):1299-1305
Objective: To provide insight into discussions at the Surgeon General's Listening Session, “Toward a National Action Plan on Overweight and Obesity,” and to complement The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity. Research Methods and Procedures: On December 7 and 8, 2000, representatives from federal, state, academic, and private sectors attended the Surgeon General's Listening Session and were given an opportunity to recommend what to include in a national plan to address overweight and obesity. The public was invited to comment during a corresponding public comment period. The Surgeon General's Listening Session was also broadcast on the Internet, allowing others to view the deliberations live or access the archived files. Significant discussion points from the Listening Session have been reviewed by representatives of the federal agencies and are the basis of this complementary document. Results: Examples of issues, strategies, and barriers to change are discussed within five thematic areas: schools, health care, family and community, worksite, and media. Suggested cooperative or collaborative actions for preventing and decreasing overweight and obesity are described. An annotated list of some programmatic partnerships is included. Discussion: The Surgeon General's Listening Session provided an opportunity for representatives from family and community groups, schools, the media, the health-care environment, and worksites to become partners and to unite around the common goal of preventing and decreasing overweight and obesity. The combination of approaches from these perspectives offers a rich resource of opportunity to combat the public health epidemic of overweight and obesity. 相似文献