Identification and characterization of a novel antioxidant peptide from feather keratin hydrolysate

Objectives

To improve the potential value of feather, which is a valuable protein resource, we have separated and identified antioxidant peptide(s) from feather hydrolysate.

Results

Feather hydrolysate was prepared by fermentation with Bacillus subtilis S1–4. Antioxidative peptides were separated by sequential acid precipitation, cation exchange, and reversed-phase fast performance liquid chromatography. Finally, a peptide with antioxidative activity was identified as Ser-Asn-Leu-Cys-Arg-Pro-Cys-Gly by MALDI time-of-flight (TOF)/TOF analysis, and determined to represent a portion of feather keratin near its N-terminal. A synthesized peptide with the same sequence was used to characterize its antioxidative properties, including scavenging free radicals, reducing power, and Fe²⁺ chelation. In terms of the peptide’s amino acid composition, the antioxidative activity might be mainly attributed to Cys and other amino acid residues.

Conclusion

Feather keratin is a good source for the quantitative preparation of antioxidative peptides.

     

Detection of a New Hainan Gibbon (<Emphasis Type="Italic">Nomascus hainanus</Emphasis>) Group Using Acoustic Call Playback

Targeted management actions informed by robust data are needed to conserve species of extreme rarity, and assessing the effectiveness of different field methods for detection and monitoring of such species is a conservation priority. Gibbons are typically detected by their daily song through passive listening surveys, but lone gibbon individuals and low-density populations are less likely to sing, making detection difficult or impossible using standard survey techniques. Call playback represents an alternative potential method for detecting gibbon presence, but there has been no empirical evaluation of the usefulness of this method in the field. We investigated the efficacy of call playback as a survey method for detecting previously unconfirmed or unknown individuals of the Critically Endangered Hainan gibbon (Nomascus hainanus), the world’s rarest primate, in patches of good-quality forest outside the current home ranges of the three known Hainan gibbon social groups in Bawangling National Nature Reserve, Hainan, China. Call playback led to detection of a male-only call likely to have been made by a solitary male, and a previously unknown social group comprising an adult male, adult female, and an infant, increasing the number of known breeding females in the global Hainan gibbon population from five to six. Call playback therefore represents an effective tool for improved monitoring of Hainan gibbons, as well as other gibbon populations; however, it is a moderately disruptive survey technique, and should be employed sparingly, in key locations, and for short periods of time only when attempting to detect gibbon presence.     

高山兀鹫繁殖期交配及筑巢行为初步观察

高山兀鹫(Gyps himalayensis)在海拔2 400~4 800 m的悬崖峭壁之上营巢,行为观测难度较大,资料匮缺。2013年至2015年,在天山采用样线调查法、问卷调查法,寻找到上百个巢穴。通过布设红外自动相机的方法,对高山兀鹫繁殖期巢内行为进行拍摄,同时结合焦点动物取样法和瞬时扫描法,对其交配及巢内行为进行观察和研究。共拍摄11万张照片,选出有效照片2 150张。对繁殖期行为进行了描述和定义,共7大类16种行为。根据照片逐一对比每种行为,统计各种行为拍摄张数及所占比例,其中,交配135张(6.3%),筑巢403张(18.7%),休息420张(19.5%),警戒375张(17.4%),保养335张(15.6%),运动200张(9.3%),其他282张(13.1%)。照片记录显示,交配行为从1月16日持续到3月2日,在一天的8:00~16:00时间段内,除9:00~10:00时没有记录到交配行为外,其余时间段内都有发生。交配行为次数(张数)在13:00~14:00时达到高峰,与气温同期达到高峰。交配过程持续8~15 s。筑巢期间,巢材由雌雄兀鹫运输,雌性负责将巢材放入巢中,整理、铺垫和修缮。筑巢行为在白天有三个高峰期,分别为11:00~12:00时、13:00~14:00时和15:00~16:00时。在每个高峰期后,往往出现一个短暂的低谷期。冬季食物短缺,照片显示雕鸮(Bubo bubo)、雪豹(Uncia uncia)等食肉动物进入巢内,对兀鹫繁殖造成干扰,甚至中断繁殖。作为高原健康指示物种,高山兀鹫生存状况不容乐观,急需加强保护。