The present study reports the application of feather hydrolysates (FHs) obtained from the hydrolysis of chicken feathers by Bacillus safensis LAU 13 (KJ461434) and Aquamicrobium defluvii FH 20 (OM281847.1) as organic nitrogen fertilizer for the cultivation of Corchorus olitorius, Celosia argentea and Amaranthus caudatus. Foliar treatment of the vegetables with FHs (100%, v/v) remarkably improved their growth and yield performances. The FHs induced over 1.5-fold improvement in root length, shoot height, shoot fresh weight, dry weight, leaf number, leaf area and chlorophyll contents of the vegetables compared to water after 6 weeks of cultivation. In most cases, FHs at optimal levels displayed better growth promotion than NPK fertilizer. FHs elevated the nitrogen content (25.53–29.79%), organic carbon (33.77–38.96%), and microbial load (10²–10⁴ cfu/g) of soil after 6 weeks. Vegetables fertilized with FHs showed improvements in crude protein, crude fibre, ash, phenols, flavonoids, and proanthocyanidin contents to controls. Also, about 1.1-fold improvement in hydrogen peroxide and DPPH radicals scavenging activities was obtained. Significant lipid peroxidation inhibition against ferrous ion (Fe²⁺) damage in precision-cut liver slices with higher catalase activities was recorded. Thus, the bacterial FHs significantly enhanced the growth, nutritional and antioxidant properties of the vegetables as well as soil nutrient and biological activities. Hence, the application of the bacterial FHs can be substituted for synthetic fertilizer to promote sustainable agricultural food production in an ecologically benign manner.

Graphical abstract

Bacterial feather hydrolysates improved growth, nutritional and nutraceutical qualities of vegetables as eco-friendly biofertilizers.

中文翻译：

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细菌羽毛水解物作为生物肥料在叶类蔬菜种植中的应用：产量、营养、植物化学、抗氧化和保肝作用

本研究报道了Bacillus safensis LAU 13 (KJ461434) 和Aquamicrobium defluvii FH 20 (OM281847.1) 水解鸡羽毛获得的羽毛水解物 (FHs) 作为有机氮肥用于培养Corchorus olitorius和Celosia argentea和苋菜. 用 FHs (100%, v/v) 对蔬菜进行叶面处理显着改善了它们的生长和产量表现。在培养 6 周后，与水相比，FHs 使蔬菜的根长、茎高、茎鲜重、干重、叶数、叶面积和叶绿素含量提高了 1.5 倍以上。在大多数情况下，最佳水平的 FHs 比 NPK 肥料表现出更好的生长促进作用。FHs 提高了氮含量 (25.53–29.79%)、有机碳 (33.77–38.96%) 和微生物负荷 (10 ² –10 ⁴ 6 周后土壤的 cfu/g)。与对照相比，用 FHs 施肥的蔬菜粗蛋白、粗纤维、灰分、酚类、类黄酮和原花青素含量有所改善。此外，过氧化氢和 DPPH 自由基清除活性也提高了约 1.1 倍。记录了具有较高过氧化氢酶活性的精密切割肝切片中对亚铁离子 (Fe ^{2+ ) 损伤的显着脂质过氧化抑制作用。}因此，细菌 FHs 显着增强了蔬菜的生长、营养和抗氧化特性以及土壤养分和生物活性。因此，细菌 FHs 的应用可以替代合成肥料，以生态友好的方式促进可持续的农业粮食生产。

图形概要

细菌羽毛水解物作为生态友好型生物肥料改善了蔬菜的生长、营养和营养品质。