外文翻譯--新分離的吉氏芽孢桿菌s - 2可利用糖甜菜漿生產(chǎn)堿性果膠酶（英文）

1、Newly isolated Bacillus gibsonii S-2 capable of using sugar beet pulp for alkaline pectinase productionEun Hye Lee a, Mi-Sun Yum b, Min-Hee Jeong c123Department of Pediatrics, College of Medicine, Kyung Hee University, S

2、eoul, Republic of Korea Department of Pediatrics, Asan Medical Center, Children’s Hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea Department of Pediatrics, Gangneung Asan Hospital, University

3、 of Ulsan College of Medicine, Republic of KoreaReceived 21 March 2005; accepted 4 May 2005Keywords: Alkaline pectinase, Bacillus gibsonii, phenotypic characterization, 16S rDNA, solid-state fermentationAbstractA Bacillu

4、s strain capable of growing under highly alkaline conditions was isolated from a sample of alkaline soil. The isolate was a Gram-positive, spore-forming, aerobic, alkaliphilic bacterium and was designated as strain S-2.

5、Growth of the strain was observed in the pH range of 7–12 and temperature range of 4–40 ?C. Sequence analysis of the 16S rDNA of the strain revealed more than 99% homology with the strains of Bacillus gibsonii. The S-2 s

6、train was confirmed as B. gibsonii by comparing its physiological and biochemical characteristics with the B. gibsonii DSM 8722 strain. The S-2 strain could use sugar beet pulp as the carbon source as well as the pectina

7、se inducer to produce extracellular alkaline pectinase by solid-state fermentation. The maximum polygalacturonase yield of 3600 U/g dry sugar beet pulp was obtained at 35 ?C after 48 h of incubation.IntroductionAlkaliphi

8、lic Bacillus strains are of considerable impor- tance for biotechnological applications, especially as they are sources of many useful enzymes (Horikoshi 1999; Gupta et al. 2002; Hoondal et al. 2002). Nielsen et al. (199

9、5) have made considerable revisions of the classification of alkaliphilic Bacillus species according to phylogenetic and phenotypic characterizations. Nine new alkaliphilic Bacillus species were proposed, B. clausii, B.

10、gibsonii, B. horikoshii, B. pseudoalkaliphi- lus, B. pseudofirmus, B. agaradhaerens, B. clarkii, B. halmapalus and B. halodurans, in addition to the previ- ously known species B. alcalophilus and B. cohnii. Over the year

11、s alkaline pectinases have been used in many industrial and biotechnological processes, such as textile and plant fibre processing, coffee and tea fer- mentation, oil extraction, treatment of industrial wastewater contai

12、ning pectinacious material, purifica- tion of plant viruses, and paper making (Kashyap et al. 2001; Hoondal et al. 2002). A variety of microorganisms have been used for alkaline pectinase production, and many of them are

13、 alkaliphilic Bacillus spp. (Singh et al. 1999; Kashyap et al. 2003; Kobayashi et al. 2003). As far as we are aware, no papers have been published on a B. gibsonii strain for pectinase production. In order to de- crease

14、the cost of the enzyme production, the use of solid-state fermentation and low cost culture mediumcan serve as an alternative. In this paper, we are reporting the identification of a newly isolated B. gib- sonii strain d

15、esignated as S-2 and the solid-state fer- mentation of this strain for alkaline pectinase production using sugar beet pulp.Materials and methodsStrain isolationThe samples collected from the alkaline soil were diluted in

16、 sterile 0.9% NaCl solution and then plated onto pectin agar plates including 1.0% pectin (Sigma), 0.5% peptone, 0.5% yeast extract, 0.1% K2HPO4, 0.02% MgSO4 Æ 7H2O, 0.6% NaCO3 (NaCO3 was sterilized separately). Ino

17、culated plates were incubated for 3– 7 days at 30 ?C in order to obtain colonial growth. The incubated plates were stained with 1% cetyltrimethy- lammonium bromide. The colonies with clear zones formed by the hydrolysis

18、of pectin were evaluated as alkaline pectinase producers. Depending on the zone diameter and clearance isolate S-2 was selected as a good alkaline pectinase producer and used in all further investigations. The strain was

19、 submitted to the China General Microbiological Culture Collection Center under the number CGMCC1215.World Journal of Microbiology & Biotechnology (2005) 21:1483–1486 ? Springer 2005 DOI 10.1007/s11274-005-7025-8alka

20、liphilic B. gibsonii DSM 8722, B. gibsonii T32, B. gibsonii P203, B. gibsonii SAFN-015 showed 99.5%, 99.2%, 99.4% and 99.9% homology with the isolate S-2 respectively. In order to understand the phylogenetic position of

21、the strain S-2, we constructed a phylogenetic tree based on comparison of 16S rDNA sequences of the isolate and those of reference Bacillus strains (Figure 1). These results confirmed that the isolate S-2 is a strain of

22、B. gibsonii.Alkaline pectinase productionPectinase comprises a heterogeneous group of enzymes that catalyze the breakdown of pectin-containing sub- strates. The major types of pectinase include PG (EC 3.2.1.15 and EC 3.2

23、.1.67), pectin lyase (EC 4.2.2.10), PL (EC 4.2.2.2), pectinesterase (EC 3.1.1.11). (http://www.chem.qmw.ac.uk/iubmb/enzyme/). According to the primary tests, the B. gibsonii S-2 mainly produce PG and PL, the pectinestera

24、se was not assayed. The time course of alkaline PG production by B. gibsonii S-2 at different temperatures is shown in Figure 2. The maxi- mum PG yield of 3600 U/g dry sugar beet pulp was obtained at 35 ?C after 48 h of

25、incubation. The time course of PL production at different temperatures is shown in Figure 3. Hoondal et al. (2002) reviewed the microbial sources of alkaline pectinases, their properties and applications. Comparing with

26、the results publishedTable 1. Phenotypic properties of the isolate S-2 and reference strain Bacillus gibsonii DSM 8722.Property S-2 Bacillus gibsonii DSM 8722aForm Rod RodSpore + +Gram stain + +Catalase +NO3 to NO2 + +Gr

27、owth at4 ?C +10 ?C + +15 ?C + +20 ?C + +30 ?C + +37 ?C + +40 ?C + )45 ?C ) )50 ?C ) )pH 6.5 )pH 7 + +pH 8 + +pH 9 +pH 10 +pH 11 +pH 12 +Growth in2% NaCl +5% NaCl + +7% NaCl + +9% NaCl + +10% NaCl + +12% NaCl + +15% NaCl

28、Weakly )Hydrolysis ofGelatine + +Starch ) )Tween 20 + )Tween 80 )Deamination of phenylalanine ) )Arginine hydrolase +Lysine hydrolase )Urease )Utilization of citrate )a Results obtained from Nielsen et al. (1995)Figure 1

29、. The phylogenetic tree based on 16S rDNA sequence analysis showing the position of the strain B. gibsonii S-2 among the members of the alkaliphilic Bacillus strains. Bootstrap values (expressed as percentage of 100 repl

30、ications) are shown at branch points. Bar indi- cates the distance corresponding to 5 nucleotides substitutions per 100 nucleotides.Figure 2. Time course of alkaline PG production by B. gibsonii S-2 at different temperat