CAJ | 학술논문

目前还田的玉米秸秆存在腐解难的特点，如何加速玉米秸秆腐解成为国内外研究的热点。该试验采用纤维素-刚果红染色法从河北山前平原小麦-玉米轮作且长期秸秆还田的土壤中分离筛选到一株纤维素酶活性高的真菌。将测得的ITS基因序列与NCBI数据库上进行同源性比对，综合形态特征和ITS基因序列同源性分析，该菌株鉴定为草酸青霉（Penicillium oxalicum）。该文对其产酶条件和玉米秸秆分解能力进行了进一步研究。结果表明，在羧甲基纤维素钠（CMC-Na）液体培养基和玉米秸秆液体培养基上30℃培养72 h，内切葡聚糖酶（CMCase酶）和滤纸酶（FPase酶）活性分别达672.8、282.9和774.6、618.3 U；以玉米秸秆为底物其产天然纤维素总酶活性可达到376.1 U，说明该菌具有较强的玉米秸秆分解能力。该菌最佳产酶条件为：0.3%的牛肉膏蛋白胨为氮源，接种量为5%，培养温度为28～35℃，pH值=4～7，培养48～96 h；最优发酵条件为固液比为1∶10，培养时间为48 h，培养温度为30℃，pH值为6.5。该菌株对玉米秸秆腐解能力的研究表明，在秸秆揺瓶试验中，培养10 d后，秸秆腐解率达87.3%，为对照的1.90倍；在土壤培养试验中，培养45 d时，腐解率达83.5%，是对照的1.62倍；在玉米秸秆还田的小麦盆栽试验中，培养65 d时，秸秆腐解率达70.8%，高于对照15.1%。因此，从原位秸秆还田土壤中筛选出来的草酸青霉对玉米有较强的腐解能力。
목전환전적옥미갈간존재부해난적특점，여하가속옥미갈간부해성위국내외연구적열점。해시험채용섬유소-강과홍염색법종하북산전평원소맥-옥미륜작차장기갈간환전적토양중분리사선도일주섬유소매활성고적진균。장측득적ITS기인서렬여NCBI수거고상진행동원성비대，종합형태특정화ITS기인서렬동원성분석，해균주감정위초산청매（Penicillium oxalicum）。해문대기산매조건화옥미갈간분해능력진행료진일보연구。결과표명，재최갑기섬유소납（CMC-Na）액체배양기화옥미갈간액체배양기상30℃배양72 h，내절포취당매（CMCase매）화려지매（FPase매）활성분별체672.8、282.9화774.6、618.3 U；이옥미갈간위저물기산천연섬유소총매활성가체도376.1 U，설명해균구유교강적옥미갈간분해능력。해균최가산매조건위：0.3%적우육고단백동위담원，접충량위5%，배양온도위28～35℃，pH치=4～7，배양48～96 h；최우발효조건위고액비위1∶10，배양시간위48 h，배양온도위30℃，pH치위6.5。해균주대옥미갈간부해능력적연구표명，재갈간요병시험중，배양10 d후，갈간부해솔체87.3%，위대조적1.90배；재토양배양시험중，배양45 d시，부해솔체83.5%，시대조적1.62배；재옥미갈간환전적소맥분재시험중，배양65 d시，갈간부해솔체70.8%，고우대조15.1%。인차，종원위갈간환전토양중사선출래적초산청매대옥미유교강적부해능력。
The decomposition of corn stalks returning to soil is very difficult. It has been the hot topic as to how to accelerate the decomposition of corn stalks in soil around the world. Isolation of cellulose-decomposing bacteria or fungiwas conducted using the method of cellulose-Congo red stain in soil with straw returning which was collected from wheat-corn rotation farmland in Hebei province. The ITS genetic sequence of the strain determined by PCR was of 99% homology with that ofPenicillium oxalicum when compared with the known sequence in the NCBI database using pairwise BLAST. The isolated strain was identified asPenicillium oxalicum on the basis of its morphological characteristics and ITS genetic sequence analysis and preserved in the China General Microbiological Culture Collection Center (CGMCC) with the preserved number of CGMCC NO.4842. The ability to decompose corn stalks and the conditions to produce enzymes by this strain were studied further. The results showed that the enzymatic activities of CMC and FPA were 672.8, 282.9 and 774.6, 618.3U when the strain was growing in the sodium carboxymethyl cellulose (CMC-Na) medium and corn stalks in the medium at 30℃ for 72h, respectively. The total activity of cellulose on a corn stalks medium reached to 376.1U. Moreover, the optimum conditions for enzyme production were 3% beef extract peptone as the nitrogen source, 5% of inoculated level , 28-35℃, pH =4-7 and cultured for 48-96 h. The best combination of pH value, temperature, solid-liquid ratio, and incubation time was pH value=6.5, 30℃, solid-liquid ratio at 1:10, and incubation for 48h. When the strain was cultured with powder of corn stalks in a growth medium for 10 days, 87.3% of the corn stalks were decomposed and 1.90 times higher than that in the control. When the strain was incubated in soil with corn stalks for 30 days, the decomposition rate was 83.5% and 1.62 times higher than that in the control. Finally, the wheat pot experiment was carried out to investigate the effect of this strain on corn stalks decomposition in soil when the plant was grown for 50 days. The result showed that the straw decomposition rate was 70.8% and 15.1% higher than that in the control. In conclusion, the strain ofPenicillium oxalicum isolated from the soil with straw returning could decompose the corn stalks efficiently.