新型生态纺织纤维

介绍了天然彩色棉纤维、甲壳素类纤维、大豆蛋白纤维、玉米纤维和牛奶酪蛋白纤维等新型生态纺织纤维的主要性能和应用状况.由于这些纤维在纺制和生产加工过程中对环境无污染,且废弃后在环境中能自然降解,符合环境保护的要求和新世纪环保纺织品的发展趋向,其开发和应用的前景良好.     

甲壳素纤维的活性染料和直接染料染色

采用活性和直接染料对甲壳素纤维、甲壳素／粘胶纤维和棉纤维进行染色。通过测定六种活性染料和八种直接染料在不同染料浓度下对甲壳素纤维、粘胶／甲壳素纤维和粘胶纤维的染色固色率，比较了它们的染色性能；考察了甲壳素纤维和棉纤维同浴染色的竞染性能。研究结果表明，甲壳素纤维的竞染能力远高于棉纤维，且在活性染料染色条件下竞染更明显；直接染料和活性染料对甲壳素纤维有相近的固色率，对粘胶纤维而言，直接染料固色率较高。     

抗菌纤维及其在针织上的应用

介绍了几种主要抗菌纤维及其特点,通过实例分析了利用抗菌纤维开发单面添纱、经编和纬编抗菌针织物的途径。     

异形涤纶/粘胶甲壳素纤维混纺转杯纱的开发

介绍了异形涤纶纤维与粘胶甲壳素纤维的原料性能和纺纱性能,分工序叙述了两种纤维混纺的转杯纺纱工艺技术措施,重点应注意防静电、防黏卷,控制好相对湿度。     

酸、碱溶液对脱脂蚕蛹组织结构的影响

在100℃下将脱脂蛹分别置于清水、盐酸溶液(1%wt)和氢氧化钠溶液(1%wt)中浸泡处理20min,采用电子光学显微分析技术,观察处理后脱脂蛹的解剖结构,并对浸泡液进行了定性分析。结果表明:(1)清水、盐酸溶液、氢氧化钠溶液浸泡,均引起蛋白质、甲壳素膨胀,氢氧化钠溶液对蚕蛹的蛋白层与甲壳层的层间有劈开作用;(2)盐酸溶液作用下,蛹蛋白的分解产物是氨基酸;蛹蛋白在碱溶液中溶解显著,同时,伴有部分蛋白质的分解,其分解产物是氨基酸,而氨基酸进一步分解可释放出氨。     

Physico-chemical characterization of fungal chitosan from shiitake stipes

Fungal chitosan was prepared by alkaline N-deacetylation of crude chitin obtained from air-dried shiitake stipes. The yields of precipitated and soluble chitosans were 218.4-240.3 and 69.3-83.4 mg/g, respectively. The degrees of N-deacetylation (DD) of precipitated chitosans increased with the prolonged reaction time and reached 90.18% at 120 min. The average molecular weights (MW) of both chitosans decreased with the prolonged reaction time. The lightness and whiteness index values of precipitated chitosans were higher than those of soluble chitosans. After N-deacetylation, carbon and nitrogen contents and N/C ratios of chitosans significantly increased. The endothermic and exothermic peak temperatures of precipitated chitosans were higher than those of soluble chitosans. Two characteristic crystalline peaks for precipitated chitosans were at 2θ=9.65° and 19.87° and three WAXD patterns were similar. Under electron microscopic examination, both chitosans showed the aggregated flakes with dense and firm structure and without porosity. Generally, both chitosans prepared showed different physico-chemical characteristics as evidenced by the DD, MW, element analysis, DSC, WAXD and SEM patterns.     

对虾加工下脚料的综合提取技术研究进展

随着我国对虾加工行业的迅速发展,产生的加工下脚料也急剧增多,主要包括虾头、虾壳和虾尾,这些下脚料中有很大一部分未被利用导致了资源浪费。工厂一般采用化学法等较简易的方法提取甲壳素、蛋白质、虾青素和虾油,得率低、纯度不高、综合利用率较差,且由于使用大量化学试剂也易造成环境污染。近期的研究发现了超临界CO₂萃取、离子液体等新的提取工艺对虾加工下脚料中营养物质的方法,不仅更环保,还能提高得率和纯度以及避免活性物质的破坏和损失。本文针对对虾加工下脚料中营养成分的提取方法进行了综述,比较并分析了化学法、酶法等传统提取技术与微生物发酵法、离子液体法、超临界及亚临界等新的工艺技术的特点,并对其综合提取技术进行了初步探讨,以期为进一步高效开发利用对虾的加工下脚料资源提供一定借鉴。     

Evaluation Antibacterial Activity of Quaternary‐Based Chitin/Chitosan Derivatives In Vitro

Abstract: Total of 3 water‐soluble quaternary‐based chitin/chitosan derivatives, which have an identical molecular weight and anion, were synthesized and characterized. Their antibacterial activities against Salmonella cholerae‐suis and Bacillus subtilis were evaluated in vitro. The polysaccharides exhibited the antibacterial efficiency. Their minimum inhibitory concentration (MIC) values vary from 0.02 to 20.48 mg/mL, and their minimum bactericidal concentration (MBC) values vary from 0.08 to 40.96 mg/mL against S. cholerae‐suis and B. subtilis, respectively. Futhermore, the extent of Bacillus subtilis cells damage was examined via transmission electron microscopy (TEM) to show how N,N,N‐trimethylchitosan (TMC) gradually destroyed and killed B. subtilis cells when they were treated with TMC. One of those quaternary polymers, O‐([2‐hydroxy‐3‐trimethylammonium])propyl chitin (OHT‐chitin), which can be directly and easily synthesized from chitin in bulk quantities, also was demonstrated its antibacterial activity. These water soluble quaternary‐based chitin/chitosan derivatives that have antibacterial effect should be potentially used as antimicrobial agents in many fields. Practical Application: The main practical application behind the investigation and evaluation antibacterial activity of 3 water‐soluble quaternary‐based chitin/chitosan derivatives could be potentially used as antimicrobial agents in many fields. These polysaccharides represent a renewable source of natural biodegradable polymers and meet with the emergence of more and more food safe problems.     

Chitin whiskers reinforced carrageenan films as low adhesion cell substrates

Carrageenan was used to prepare carrageenan films reinforced with chitin nanowhiskers. Atomic force microscopy was used to characterize the morphology and roughness of the films. Structural characterization was performed using X-ray diffraction and Fourier transform infrared spectroscopy. The mechanical properties were assessed by tensile tests. The prepared nanocomposites were used as cell substrate in order to explore their potential biological applications. HeLa cells were seeded on the samples in order to assess their biocompatibility. The preliminary results show good cell proliferation but low cell adhesion, demonstrating a potential application of this novel material as substrate for tumor cell culture.     

Molecular cloning and sequencing of a chitin synthase gene (CHS2) of Paracoccidioides brasiliensis

The nucleotide sequence of a chitin synthase gene (CHS2) of the dimorphic fungal human pathogen Paracoccidioides brasiliensis has been determined. The deduced amino acid sequence of Chs2p consists of 1043 residues and is highly homologous to other class II fungal chitin synthases. Computational structural analyses suggest very high similarity to other fungal chitin synthases with a highly variable region at the cytosolic amino-terminal region which may be related to its possible zymogenic nature, and the putative catalytic region close to seven membrane-spanning regions at the carboxyl terminus. The nucleotide sequence of CHS2 and its flanking regions has been submitted to GenBank under Accession Number Y09231. © 1998 John Wiley & Sons, Ltd.