CAJ | 학술논문

香蕉纤维的开发利用是香蕉茎秆资源综合利用的有效突破口。该研究以中国主栽品种巴西蕉香蕉茎秆纤维为研究对象，采用俐迪链霉菌对其进行生物脱胶，研究其产酶和脱胶的条件并对脱胶后纤维的结构和理化性质进行分析。研究结果表明：俐迪链霉菌在果胶和半纤维素筛选培养基中观察到明显的水解圈，具有水解果胶和半纤维素的能力；以残胶率和果胶酶活性为指标，筛选出产酶和脱胶的条件为：pH值5.0、NH4NO34 g/L、麸皮10 g、接种量9 mL，在此条件下菌体产酶活力为75μg/(mL·min)，香蕉纤维残胶率4.80%，纤维得率为59.48%；扫描电镜（scanning electron microscope，SEM）结果显示脱胶后纤维的直径和表面结构发生了改变；脱胶后纤维的强力从345.37 cN降至273.37 cN，纤维的细度由18.55 tex增加至8.91 tex；纤维中的纤维素含量增加，半纤维素、木质素和果胶等非纤维素成分明显减少，致使脱胶后的纤维素热稳定性和结晶度都明显增加，这一结果与SEM、X射线衍射（X-ray diffraction，XRD）和傅立叶红外光谱（Fourier transform infrared spectroscopy，FTIR）分析结果一致；表明该菌株在香蕉纤维脱胶方面具有一定的应用前景。
향초섬유적개발이용시향초경간자원종합이용적유효돌파구。해연구이중국주재품충파서초향초경간섬유위연구대상，채용리적련매균대기진행생물탈효，연구기산매화탈효적조건병대탈효후섬유적결구화이화성질진행분석。연구결과표명：리적련매균재과효화반섬유소사선배양기중관찰도명현적수해권，구유수해과효화반섬유소적능력；이잔효솔화과효매활성위지표，사선출산매화탈효적조건위：pH치5.0、NH4NO34 g/L、부피10 g、접충량9 mL，재차조건하균체산매활력위75μg/(mL·min)，향초섬유잔효솔4.80%，섬유득솔위59.48%；소묘전경（scanning electron microscope，SEM）결과현시탈효후섬유적직경화표면결구발생료개변；탈효후섬유적강력종345.37 cN강지273.37 cN，섬유적세도유18.55 tex증가지8.91 tex；섬유중적섬유소함량증가，반섬유소、목질소화과효등비섬유소성분명현감소，치사탈효후적섬유소열은정성화결정도도명현증가，저일결과여SEM、X사선연사（X-ray diffraction，XRD）화부립협홍외광보（Fourier transform infrared spectroscopy，FTIR）분석결과일치；표명해균주재향초섬유탈효방면구유일정적응용전경。
To date, there is little information on the degumming technology byStreptomyces lydicus for banana fibers destined for textiles. Furthermore, the retted efficiency and characterization of banana fiber has not yet been found in literatures. In this study, banana fiber (Musa spp. Baxijiao) bio-degumming at laboratory scale with controlled inoculation using selected strain (Streptomyces lydicus) and physicochemical characteristics of retted banana fiber were investigated. The hydrolysis activity of selected strain was conducted by pectin and hemicelluloses culture. Clear zones were visualized on pectin-agar and hemicelluloses-agar plates. Effect of fermentation conditions (temperature, pH, nitrogen source, carbon source and inoculums size) on banana fiber degumming was evaluated based on the content of residual gum and activity of pectin lyase. The results indicated that the optimum degumming medium of strain was pH value 5.0, NH4NO3 4 g/L, wheat bran 10 g and inoculums size 9 mL. After cultivating for 72 h, the activity of pectinase was 75μg/(mL·min), the residual gum of banana fiber was 4.86%, the yield of retted banana fiber was 59.48% (dry weight). Structural and surface analysis of the degumming banana fibers showed a reduction in diameter and changes in surface morphology from that of the raw fibers. The average range of the fiber diameters were approximately 5-10μm, which was lower (p<0.05) than the average size of the fiber bundles before treatment. This reduction in the fiber diameter was due to the dissolution of hemicelluloses and lignin, which was confirmed by the chemical analysis and Fourier Transformation Infrared Spectroscope (FTIR) graphs. The treated fibers showed higher (p<0.05) percentages of cellulose (43.13% to 69.88%) and lower (p<0.05) percentages of hemicelluloses (18.85% to 10.89%), lignin (14.05 to 9.06), pectin (3.43% to 1.91%), and wax (12.24% to 5.77%) compared with untreated fibers. The physical property of fibers were analyzed according to the GB standards(GB5889-1986) and showed an increase in fineness (18.55 to 8.91 tex), and a decrease in break strength (345.37 to 237.37 cN) for the retted fibers. A small weight loss was found from 50 to 100℃, and this loss was primarily attributed to moisture and solvent evaporation or to the low-molecular- weight compounds remained after the isolation procedures. The fiber thermal stability for temperature ranging between 200 and 300℃ was primarily due to the depolymerization of non-cellulose, such as hemicelluloses, and the cleavage of glycosidic linkages of cellulose to form levoglucosan (1,6-anhydro-β-D-glucopyranose) and carbon residues. The decomposition of lignin occurred in the region from 200 to 500℃. The thermogram of the raw banana fiber indicated a greater resistance to degradation in the range of 354 to 527℃ due to the presence of larger amounts of hemicelluloses and lignin, the maximum degradation rate was found during theα-cellulose decomposition of raw and treated banana fibers at 287.45 and 349.04℃ (mass loss = 87.24%), respectively. The thermal analysis showed that the thermal stability of the treated fibers was improved. The XRD pattern of retted fiber, which exhibited an increased crystallinity (11.8% to 52.6%), gives a relatively intense peak at 2θ = 23.87°, and hydrolysis took place preferentially in the amorphous region. In all, the results showed that theStreptomyces lydicusstain had good applying prospects in microbial retting and enzymatic retting of banana fiber.