Ultraviolet protection and antibacterial properties of silk fabric dyed with Cinnamomum camphora plant leaf extract

In this study, natural dyes have been extracted from camphor plant (Cinnamomum camphora) dry leaves in alkaline medium and are then applied on to silk fabric by exhaust dyeing process. The UV protection, antimicrobial property, color strength values and colorfastness of the silk dyed with plant extract are studied. The results show that the fabric samples treated with extract have excellent UV protection properties and are very effective in blocking UVA and UVB radiations. The fabric dyed with natural extract shows antimicrobial properties, which is proved by bacterial reduction in quantitative tests. The color fastness to washing and rubbing is found very good to excellent and color fastness to light is poor. Silk fabric dyed for less time shows golden color, while the increased dyeing time shows reddish-brown color. The UV protection and antimicrobial performance of camphor plant leaf extract are found excellent

Metabolic engineering of Ashbya gossypii for limonene production from xylose

BACKGROUND: Limonene is a cyclic monoterpene that has applications in the food, cosmetic, and pharmaceutical industries. The industrial production of limonene and its derivatives through plant extraction presents important drawbacks such as seasonal and climate issues, feedstock limitations, low efficiency and environmental concerns. Consequently, the implementation of efficient and eco-friendly bioprocesses for the production of limonene and other terpenes constitutes an attractive goal for microbial biotechnology. In this context, novel biocatalysts with the ability to produce limonene from alternative carbon sources will help to meet the industrial demands of limonene. RESULTS: Engineered strains of the industrial fungus Ashbya gossypii have been developed to produce limonene from xylose. The limonene synthase (LS) from Citrus limon was initially overexpressed together with the native HMG1 gene (coding for HMG-CoA reductase) to establish a limonene-producing platform from a xylose-utilizing A. gossypii strain. In addition, several strategies were designed to increase the production of limonene. Hence, the effect of mutant alleles of ERG20 (erg20(F95W) and erg20(F126W)) were evaluated together with a synthetic orthogonal pathway using a heterologous neryl diphosphate synthase. The lethality of the A. gossypii double mutant erg20(F95W−F126W) highlights the indispensability of farnesyl diphosphate for the synthesis of essential sterols. In addition, the utilization of the orthogonal pathway, bypassing the Erg20 activity through neryl diphosphate, triggered a substantial increase in limonene titer (33.6 mg/L), without critically altering the fitness of the engineered strain. Finally, the overexpression of the native ERG12 gene further enhanced limonene production, which reached 336.4 mg/L after 96 h in flask cultures using xylose as the carbon source. CONCLUSIONS: The microbial production of limonene can be carried out using engineered strains of A. gossypii from xylose-based carbon sources. The utilization of a synthetic orthogonal pathway together with the overexpression of ERG12 is a highly beneficial strategy for the production of limonene in A. gossypii. The strains presented in this work constitute a proof of principle for the production of limonene and other terpenes from agro-industrial wastes such as xylose-rich hydrolysates in A. gossypii. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13068-022-02176-0