The unique GH5 cellulase member in the extreme halotolerant fungus Aspergillus glaucus CCHA is an endoglucanase with multiple tolerance to salt, alkali and heat: prospects for straw degradation applications

Extremophiles ◽  
2018 ◽  
Vol 22 (4) ◽  
pp. 675-685 ◽  
Author(s):  
Zhengqun Li ◽  
Xue Pei ◽  
Ziyu Zhang ◽  
Yi Wei ◽  
Yanyue Song ◽  
...  

A strain of the homothallic ascomycete Aspergillus glaucus was isolated from nature and found to produce sectors continually during subculturing (figure 25, plate 18). Sectors (here called the ' A ’ type) on certain media differ quantitatively from the original parent mycelium (the ‘ B ’ type) in at least five characters, the most easily observable being greatly enhanced conidium formation. When propagated asexually and sexually the ‘ A ’ and ‘ B ’ types behave in an unexpected manner (figure 24, observation, also Subak Sharpe 1956 a,b ). When subculturing from ‘ A ’ type is done with inocula of large overall cytoplasmic volume, that is, when colonies are started from hyphal tips, mycelium blocks or masses of either ascospores or conidia, then only ‘A ’ type colonies are formed.But when new cultures initiate from small cytoplasmic volumes, i.e. when conidial suspensions or ascospores from single perithecia are dilution plated, then some spores germinate to give ‘ A ’ colonies and the others ' B ' colonies. The relative proportions can vary greatly and depend on the parent colony’s medium, the age of the spores and other factors. Ascospore segregations from single perithecia actually frequently mimic 1:1 single nuclear gene segregation. (Ascospores of this strain are haploid and uninucleate in origin, conidia are binucleate in origin.)


2017 ◽  
Vol 52 (1) ◽  
Author(s):  
Isabella Grishkan ◽  
Marina Temina

<em>Aspergillus glaucus</em><span> is a fungus able to tolerate low water activity of the environment. Its dense growth and sporulation were found on basaltic stones with epilithic lichens after 14 years of storage at a temperature of 4–7°C and relative humidity of 14–18%. Dust and soil particles deposited on the lichen thalli and dissolved in the water condensed on the stones during the storage period, apparently served as a nutrient source for the fungus. Probably, strongly xeric water regime on basaltic stones suitable for <em>A. glaucus</em> did not allow mesophilic fungi to develop and prevented the xerotolerant fungus from competition with other microfungi for nutrient sources. It is also possible that specific cellular mechanism associated with the production of chaotropic compounds (such as glycerol) supported germination and development of <em>A. glaucus</em> at low temperatures, which were considered non-optimal for the fungus.</span>


1995 ◽  
Vol 58 (9) ◽  
pp. 1018-1022 ◽  
Author(s):  
SARATH K. KATTA ◽  
LLOYD B. BULLERMAN

White and yellow popcorn were stored in different containers at high temperature (35°C) and high relative humidity (85%) conditions for 3 months. Gradual decreases in popping volumes with the lengthening of storage time were observed in both white and yellow popcorn. Internal mold infection was quite low in both white (5.7%) and yellow (3.0%) popcorn at the beginning of storage tests. Few differences were found in total infection levels up to 60 days of storage, except that the Aspergillus glaucus group became established in place of field fungi. A gradual increase in mold infection levels was then observed during the remaining 30 days of storage. Visible mold growth was also observed on the tips of some kernels by the end of storage studies. Internal mold infection in white popcorn stored in an open container was lower (18.3%) than white popcorn stored in a closed plastic bag (75.0%) and closed plastic jar (85.3%), whereas the internal mold infection in yellow popcorn stored in an open container was higher (23.3%) than yellow popcorn stored in a closed plastic bag (6.3%) and closed plastic jar (2.6%). The A. glaucus group were the predominant molds found at the end of storage tests. The ability of toxigenic molds to invade the popcorn was determined using a dry spore inoculum. None of the inoculated molds, which included Aspergillus flavus, Penicillium martensii, and Penicillium viridicatum, were able to invade the popcorn during storage. However, the A. glaucus group predominated at the end of storage tests in the inoculated samples.


2010 ◽  
Vol 14 (10) ◽  
pp. 1074-1078 ◽  
Author(s):  
Tatiana da S. Santos ◽  
Francisco de A. C. Almeida ◽  
Taís de M. F. Suassuna ◽  
Wirton M. Coutinho ◽  
Pollyne B. A. Almeida

A radiação gama, proveniente da fonte de 60Co, é bastante utilizada para esterilização, visando a prevenção da decomposição e a toxidez de origem microbiana em diversos produtos. O grau de radiossensibilidade de um embrião vegetal depende da espécie, do estágio de seu desenvolvimento durante a radiação, da dose empregada e do critério usado para medir o efeito biológico, sendo comumente utilizado o teste de germinação. Objetivou-se, com este trabalho, estudar a sensibilidade do amendoim a radiação gama e seus efeitos na germinação, no vigor e na micoflora das sementes da cultivar BRS Havana, irradiadas com uma fonte de 60Co, tipo gammacell, com taxa de dosagem de 12,5 kGy h-1. As doses testadas em kGy foram as seguintes: 0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 6,0; 9,0; 12,0; 15,0; 18,0; 21,0 e 24,0. Com os resultados obtidos, concluiu-se que as doses acima de 3,0 kGy prejudicaram a viabilidade das sementes e as doses acima de 12 kGy comprometeram totalmente o vigor e a germinação das sementes de amendoim. A radiação a partir da dose 2,0 kGy eliminou os fungos Aspergillus flavus e Aspergillus niger e, a partir da dose 3,0 kGy, eliminou o Aspergillus glaucus. O Penicilium spp. permaneceu em mais de 30% das sementes em todos os tratamentos com radiação, não sendo eliminado até a dose de 24 kGy.


2012 ◽  
Vol 14 (6) ◽  
pp. 665-671 ◽  
Author(s):  
Menghao Cai ◽  
Xiangshan Zhou ◽  
Jian Lu ◽  
Weimin Fan ◽  
Jiushun Zhou ◽  
...  

2007 ◽  
Vol 63 (11) ◽  
pp. o4196-o4196
Author(s):  
Wen-liang Wang ◽  
Hong-wen Tao ◽  
Wei Sun ◽  
Qian-Qun Gu ◽  
Wei-Ming Zhu

The title compound, C21H32O3, also known as dimethylincisterol A3, was isolated from halotolerant fungus THW-18. It is composed of three fused rings and a side chain. In the crystal structure, the molecules interact with each other via O—H...O hydrogen bonds, resulting in an extended chain along the b axis. The absolute configuration was assigned from the measured optical rotation and reference to the literature.


Life ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 31 ◽  
Author(s):  
Alessia Marchetta ◽  
Bert Gerrits van den Ende ◽  
Abdullah Al-Hatmi ◽  
Ferry Hagen ◽  
Polona Zalar ◽  
...  

A global set of clinical and environmental strains of the halotolerant black yeast-like fungus Hortaea werneckii are analyzed by multilocus sequencing and AFLP, and physiological parameters are determined. Partial translation elongation factor 1-α proves to be suitable for typing because of the presence/absence of introns and also the presence of several SNPs. Local clonal expansion could be established by a combination of molecular methods, while the population from the Mediterranean Sea water also responds differently to combined temperature and salt stress. The species comprises molecular populations, which in part also differ physiologically allowing further diversification, but clinical strains did not deviate significantly from their environmental counterparts.


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