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http://onlinelibrary.wiley.com/journal/10.1111/%28ISS
N%291749‐4877;
http://onlinelibrary.wiley.com/subject/code/00006
1/homepage/iubs_virtual_issue.htm
Isolation <strong>and</strong> characterization of <strong>the</strong>
Larixgmelinii UGDH gene
Ningning LI, 1 Li WANG, 1 Wenbo ZHANG 2
<strong>and</strong>Xiaofei LIN 1
5.74, that shows striking sequence similarity <strong>to</strong> UGDH
proteins from Cinnamomum osmophloeum<strong>and</strong>
Piceasitchensis. The protein structure prediction shows
that <strong>the</strong> LgUGDH is a cy<strong>to</strong>solic protein, which has a
membrane‐associated region in its N‐teminal. For
investigating character of <strong>the</strong> LgUGDH, a xxx‐bp of <strong>the</strong>
LgUGDH promoter was isolated, <strong>and</strong> plasmids of
pUC18‐LgUDGH:GFP <strong>and</strong> pBI101‐LgUGDH were
constructed. The character of <strong>the</strong> LgUGDH will be
investigated by transforming Arabidopsis thaliana.
1College of Life Sciences, Inner Mongolia University, Hohhot
010021, China <strong>and</strong> 2College of Forestry, Inner Mongolia
Agricultural University, Hohhot 010019, China.
Isolation of cold­active alkaline cellulase
producing actinomycete <strong>and</strong> investigation of
its enzyme properties
Dahurian Larch, Larix gmelinii (Rupr.), is 1 of 3 major
timber conifers in nor<strong>the</strong>ast China, which has straight
timber, clear wood texture, compact wood <strong>and</strong> natural
color. In addition, fiber cells of <strong>the</strong> larch are longer, <strong>and</strong>
<strong>the</strong> content of nonfiber cells is lower, so that <strong>the</strong> L.
gmelinii has important economic value in <strong>the</strong> building,
decoration, paper production <strong>and</strong> chemical fiber
industry. However, because <strong>the</strong> ecological amplitude of
<strong>the</strong> larch is very large, significant difference in <strong>the</strong>
physical <strong>and</strong> mechanical properties <strong>and</strong> processing
properties generally can be found in <strong>the</strong> larch from
different habitats. Therefore, it is very important <strong>to</strong>
choose eximious seedlings for afforestation, <strong>and</strong> <strong>to</strong>
improve timber quality by controlling expression of
genes related <strong>to</strong> wood formation.
The cell wall consists <strong>to</strong> a large part of different
polysaccharides, <strong>and</strong> approximately 50% of those
originate from UDP‐glucuronate. UDP‐glucuronate is a
key precursor for <strong>the</strong> syn<strong>the</strong>sis of hemicelluloses <strong>and</strong>
pectins for <strong>the</strong> cell wall formation. UDP‐glucuronate is
formed from UDP‐glc by UDP‐glc dehydrogenase (UGDH),
<strong>and</strong> UGDH has been suggested <strong>to</strong> be an important
rate‐limiting enzyme in <strong>the</strong> pathways leading <strong>to</strong>
hemicellulose <strong>and</strong> pectin formation. Therefore, it is
necessary <strong>to</strong> isolate UGDH gene from L. gmelinii, <strong>and</strong> <strong>to</strong>
analyze expression pattern, function <strong>and</strong> mechanism of
<strong>the</strong> gene.
In <strong>the</strong> study, an ortholog of UGDH, referred <strong>to</strong> as LgUGDH,
was isolated by degenerate PCR <strong>and</strong> RACE from L.
gmelinii. The 1904bp of full‐length LgUGDH cDNA is
predicted <strong>to</strong> encode a protein of 481 amino acids with a
molecular mass of 52.62 kDa <strong>and</strong> a isoelectric point of
Qiang LI, Juanjuan FEI, Gengsheng JI, Xuding GU
<strong>and</strong> Zaiqiang WU
School of Biology <strong>and</strong> Chemical Engineering, Jiangsu University
of Science <strong>and</strong> Technology, Zhenjiang 212018, China. Email:
biojustlq@yahoo.cn
This work aimed <strong>to</strong> isolate cold‐active alkaline cellulase
producing strain, produce <strong>the</strong> unique cellulase with low
cost <strong>and</strong> carry out hydrolysis in alkaline enviroment at
low temperature. Sixteencellulose‐producing strains were
isolated from mulberry rhizosphere soil in winter. A
cold‐active cellulase producingactinomycete strain BJ‐XH
was isolated using methods of CMC clear haloes, congo
red dying <strong>and</strong> cellulase activities detection. It was
identified belonging <strong>to</strong> Nocardiopsis. Conditions of
cellulase production via fermentatation, enzyme
constitutions <strong>and</strong> characteristics of strain BJ‐XH were
investigated. The results indicated that strain BJ‐XH is a
aerobic, alkaline actinomycete. The optimal condition for
cellulase production was 28℃, pH 8.5 <strong>and</strong> <strong>the</strong> inoculation
dose was 6% in shaking flask culture for 6–8 days. This
strain can produce alkaline cellulase, which was mainly
composed of Cx enzyme. The enzyme activity can reach
3.6 IU/mL at 20℃ <strong>and</strong> pH 9.0 (optimal catalysis
conditions). In addition, Mn 2+ , Fe 3+ <strong>and</strong> Co 2+ could
stimulate <strong>the</strong> enzyme reaction, while Cu 2+ <strong>and</strong> Pb 2+ inhibit
<strong>the</strong> enzyme activity. The cellulase is a promising regeant
for low temperature applications in detergents <strong>and</strong> fibroin
fibre treatment.
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