Degumming Research Articles

Fine mapping and candidate gene analysis of qSRC3 controlling the silk color in maize (Zea mays L.).

Fine mapping of the maize QTL qSRC3, responsible for red silk, uncovered the candidate gene ZmMYB20, which encodes an R2R3-MYB transcription factor, has light-sensitive expression, and putatively regulates genes expression associated with anthocyanin biosynthesis. Colorless silk is a key characteristic contributing to the visual quality of fresh corn intended for market distribution. Nonetheless, the identification of Mendelian trait loci and associated genes that control silk color has been scarce. In this study, a F2 population arising from the hybridization of the single-segment substitution line qSRC3MT1 with red silk, carrying an introgressed allele from teosinte (Zea mays ssp. mexicana), and the recurrent maize inbred line Mo17, characterized by light green silk, was utilized for fine mapping. We found that the red silk trait is controlled by a semi-dominant genetic locus known as qSRC3, and its expression is susceptible to light-mediated inhibition. Moreover, qSRC3 explained 68.78% of the phenotypic variance and was delimited to a 133.2kb region, which includes three genes. Subsequent expression analyses revealed that ZmMYB20 (Zm00001d039700), which encodes an R2R3-MYB transcription factor, was the key candidate gene within qSRC3. Yeast one-hybrid and dual-luciferase reporter assays provided evidence that ZmMYB20 suppresses the expression of two crucial anthocyanin biosynthesis genes, namely ZmF3H and ZmUFGT, by directly binding to their respective promoter regions. Our findings underscore the significance of light-inhibited ZmMYB20 in orchestrating the spatial and temporal regulation of anthocyanin biosynthesis. These results advance the production of colorless silk in fresh corn, responding to the misconception that fresh corn with withered colored silk is not fresh and providing valuable genetic resources for the improvement of sweet and waxy maize.

Custom-designed, mass silk production in genetically engineered silkworms.

Genetically engineered silkworms have been widely used to obtain silk with modified characteristics especially by introducing spider silk genes. However, these attempts are still challenging due to limitations in transformation strategies and difficulties in integration of the large DNA fragments. Here, we describe three different transformation strategies in genetically engineered silkworms, including transcription-activator-like effector nuclease (TALEN)-mediated fibroin light chain (FibL) fusion (BmFibL-F), TALEN-mediated FibH replacement (BmFibH-R), and transposon-mediated genetic transformation with the silk gland-specific fibroin heavy chain (FibH) promoter (BmFibH-T). As the result, the yields of exogenous silk proteins, a 160 kDa major ampullate spidroin 2 (MaSp2) from the orb-weaving spider Nephila clavipes and a 226 kDa fibroin heavy chain protein (EvFibH) from the bagworm Eumeta variegate, reach 51.02 and 64.13% in BmFibH-R transformed cocoon shells, respectively. Moreover, the presence of MaSp2 or EvFibH significantly enhances the toughness of genetically engineered silk fibers by ∼86% in BmFibH-T and ∼80% in BmFibH-R silkworms, respectively. Structural analysis reveals a substantial ∼40% increase in fiber crystallinity, primarily attributed to the presence of unique polyalanines in the repetitive sequences of MaSp2 or EvFibH. In addition, RNA-seq analysis reveals that BmFibH-R system only causes minor impact on the expression of endogenous genes. Our study thus provides insights into developing custom-designed silk production using the genetically engineered silkworm as the bioreactor.

Fibroin Nanoparticles: Use in Drug Delivery

The silkworm Bombyx mori.L. is infected by various diseases viz; grasserie, flacherie, muscardine, and pebrine. Among all these diseases the grasserie causes major economic loss to the industry and is one of the main reasons for low silk productivity. It is caused by a virus known as Bombyx mori nucleopolyhedro virus (BmNPV). The impact of grasserie disease on silkworms is significant as it leads to reduced silk production and can result in economic losses for sericulture farmers. In India greater than 50% of silk cocoon crop loss is due to BmNPV [1] and in Kashmir valley, the loss is about 28-32% [2]. Silk obtained from the cocoons of silkworm Bombyx mori L. is a natural fibrous protein well known for being lightweight, having high mechanical strength, good flexibility, and luster making it ideal for the textile industry. In addition, fibroin extracted from the cocoons of domesticated silkworm Bombyx mori L. has gained growingly interest due to its excellent mechanical properties and high biocompatibility, biodegradability, inexpensiveness, and preparation flexibility [3]. These properties of silk fibroin lead to the formulation of fibroin nanoparticles (FNP’-s) which can be used to encapsulate different types of therapeutic compounds like proteins, vaccines, enzymes, etc. Fibroin has been approved as a biomaterial by the Food and Drug Administration (FDA) and has been popularly used in numerous medical applications such as sutures, tissue regeneration, coating devices, and drug delivery systems [4]. It has been studied that SF-derived curcumin nanoparticles show higher efficacy against breast cancer cells and have the potential to treat in vivo breast tumors by local, sustained, and long-term therapeutic delivery as a biodegradable system [5]. Therefore, fibroin-coated nanoparticles can be used effectively for disease management.

Thermochemical conversion of silkworm by-product into syngas

This study explored the valorisation of silkworm by-product, a major by-product of the silk industry (sericulture), which amounts to 16 million tonnes annually. The focus was on transforming waste into energy resources through pyrolysis under CO2 conditions. In one-stage pyrolysis, the evolution of syngas under N2 was found to be comparable to that under CO2. A notable allocation of carbon to biocrude rather than syngas was observed. The two-stage pyrolysis resulted in increased syngas production. However, achieving a homogeneous reaction between CO2 and the volatiles liberated from silkworm byproduct proved challenging. Indeed, the reaction kinetics governing CO2 reactivity was not fast although the temperature windows of the reaction were aligned in the two-stage pyrolysis. To address this issue, pyrolysis was performed using a Ni-based catalyst to expedite the reaction kinetics. Consequently, syngas formation, particularly CO formation, was significantly enhanced under CO2 conditions compared to that under N2 conditions. The syngas yield under CO2 was 36.42 wt% which was 2-fold higher than that of N2. This suggested the potential of CO2 altering the carbon distribution from biocrude to syngas. This strategy would contribute to the establishment of sustainable production of silk by converting sericulture by-product into energy/chemical resources.

Review of Spider Silk Applications in Biomedical and Tissue Engineering.

This review will present the latest research related to the production and application of spider silk and silk-based materials in reconstructive and regenerative medicine and tissue engineering, with a focus on musculoskeletal tissues, and including skin regeneration and tissue repair of bone and cartilage, ligaments, muscle tissue, peripheral nerves, and artificial blood vessels. Natural spider silk synthesis is reviewed, and the further recombinant production of spider silk proteins. Research insights into possible spider silk structures, like fibers (1D), coatings (2D), and 3D constructs, including porous structures, hydrogels, and organ-on-chip designs, have been reviewed considering a design of bioactive materials for smart medical implants and drug delivery systems. Silk is one of the toughest natural materials, with high strain at failure and mechanical strength. Novel biomaterials with silk fibroin can mimic the tissue structure and promote regeneration and new tissue growth. Silk proteins are important in designing tissue-on-chip or organ-on-chip technologies and micro devices for the precise engineering of artificial tissues and organs, disease modeling, and the further selection of adequate medical treatments. Recent research indicates that silk (films, hydrogels, capsules, or liposomes coated with silk proteins) has the potential to provide controlled drug release at the target destination. However, even with clear advantages, there are still challenges that need further research, including clinical trials.

A Comprehensive Review of Insect Pest Management in Muga Silkworm (Antheraea assamensis Helfer): Current Scenario and Future Prospects

Muga silkworm (Antheraea assamensis Helfer), renowned for its natural production of prized golden silk, is native to Assam and adjacent regions in North-Eastern India. However, outdoor rearing of Muga silkworms exposes them to environmental fluctuations year-round, resulting in significant crop losses due to insect pests. Notably, pre-seed crops (Aherua and Jarua) and seed crops (Chotua and Bhodia) experience significantly higher losses compare to commercial crops (Jethua and Kotia). This paper presents a thorough analysis of insect pests impacting Muga silkworm rearing, classified according to activity periods and intensity of attacks. Primary insect pests include Exorista sorbillans (Uzi fly), Apanteles glomeratus (Brachonid fly), ants and wasps. Uzi fly inflicts damage during winter (November to February), primarily affecting 4th and 5th instar Muga larvae, leading to substantial losses during cocoon harvest in March-April, jeopardizing seed production for subsequent Jethua (April-May) commercial crops. Apanteles glomeratus and ants pose threats during summer. Vespa orientalis (wasp) causes damage to late instars from April to September. Chemical control methods are discouraged due to their adverse effects on silkworms. Therefore, urgent research into environmentally sustainable pest management strategies tailored to Muga rearing's specific needs and limitations are warranted. This review synthesizes detailed descriptions of identified pests, challenges in insect pest management, and discusses various mitigation strategies, offering insights into the biology of major insect pests affecting Muga silkworms and evaluating the effectiveness of different pest management approaches.

G-quadruplex is involved in the regulation of BmSGF1 expression in the Silkworm, Bombyx mori.

Advanced DNA structures, such as the G-quadruplex (G4) and the i-motif, are widely but not randomly present in the genomes of many organisms. A G4 structure was identified in the promoter of the silk gland factor-1 gene (SGF1), which is the main regulatory gene for silk production in Bombyx mori. In this study, a BmSGF1 G4-/- homozygous mutant was generated with the G4 sequence knocked out. The promoter activity of BmSGF1 was lowered in the BmSGF1G4-/- mutant. Pyridostatin (PDS) stabilized the G4 structure and increased the promoter activity of BmSGF1, whereas anti-sense oligonucleotide (ASO) complementary to the G4 sequence suppressed the promoter activity of BmSGF1. Compared with wild-type larvae, the deletion of the BmSGF1 G4 structure decreased both the expression of BmSGF1 and the fibroin heavy chain gene BmFib-H in the posterior silk gland and the weight of the cocoons. Overall, these results suggest that the promoter G4 structure of BmSGF1 participates in the transcription regulation of the BmSGF1 gene in the silkworm.

Revealed comparative advantage analysis of trade of Indian silk and silk products

Revealed comparative advantage analysis of trade of Indian silk and silk products

Harvesting Silk Fibers from Plodia interpunctella: Role of Environmental Rearing Conditions in Fiber Production and Properties.

Silk fibers are produced by a wide variety of insects. The silkworm Bombyx mori (Bombyx) was domesticated because the physical properties of its silk fibers were amenable to the production of fine textiles. Subsequently, engineers have regenerated silk fibroin to form biomaterials. The monocular focus on Bombyx silk has underutilized the expanse of diverse silk proteins produced by more than 100,000 other arthropods. This vast array of silk fibers could be utilized for biomedical engineering challenges if sufficient rearing and purification processes are developed. Herein, we show that the moth, Plodia interpunctella (Plodia), represents an alternative silk source that is easily reared in highly regulated culture environments allowing for greater consistency in the silk produced. We controlled the temperature, resource availability (larvae/gram diet), and population density (larvae/mL) with the goal of increasing silk fiber production and improving homogeneity in Plodia silk proteins. We determined that higher temperatures accelerated insect growth and reduced life cycle length. Furthermore, we established initial protocols for the production of Plodia silk with optimal silk production occurring at 24 °C, with a resource availability of 10 larvae/gram and a population density of 0.72 larvae/mL. Population density was shown to be the most prominent driving force of Plodia silk mat formation among the three parameters assessed. Future work will need to link gene expression, protein production and purification, and resulting mechanical properties as a function of environmental cues to further transition Plodia silk into regenerated silk fibroin biomaterials.

A Comprehensive Examination of Silk Production and Its Socioeconomic Implications in Sericulture in India

A Comprehensive Examination of Silk Production and Its Socioeconomic Implications in Sericulture in India

Survey on Sericulture: An IOT-based Cocoon Worms Monitoring for Disease Identification and Management for Quality Silk Rearing.

The sericulture industry in India, plays a vital role in the economy, with silk production contributing significantly to the country's textile sector. However, the industry faces challenges due to the detrimental impact of diseases on silk production. To address this issue, this project proposes a comprehensive monitoring system that integrates sensors for temperature, humidity, and light levels, alongside machine learning algorithms for the early detection of common silkworm diseases such as pebrine, flacherie, etc. By ensuring optimal rearing conditions and proactively managing disease outbreaks, the model aims to minimize production losses and enhance silk yield. Given the importance of silk in India's textile industry, increasing yield is crucial for meeting domestic demand, promoting exports, and bolstering economic growth. Through the adoption of advanced technologies and proactive disease management strategies, this project seeks to strengthen the sericulture sector and secure a sustainable future for silk production in India

CRISPR/Cas9-Mediated Editing of BmEcKL1 Gene Sequence Affected Silk Gland Development of Silkworms (Bombyx mori).

The silkworm (Bombyx mori) has served humankind through silk protein production. However, traditional sericulture and the silk industry have encountered considerable bottlenecks and must rely on major technological breakthroughs to keep up with the current rapid developments. The adoption of gene editing technology has nevertheless brought new hope to traditional sericulture and the silk industry. The long period and low efficiency of traditional genetic breeding methods to obtain high silk-yielding silkworm strains have hindered the development of the sericulture industry; the use of gene editing technology to specifically control the expression of genes related to silk gland development or silk protein synthesis is beneficial for obtaining silkworm strains with excellent traits. In this study, BmEcKL1 was specifically knocked out in the middle (MSGs) and posterior (PSGs) silk glands using CRISPR/Cas9 technology, and ΔBmEcKL1-MSG and ΔBmEcKL1-PSG strains with improved MSGs and PSGs and increased silk production were obtained. This work identifies and proves that BmEcKL1 directly or indirectly participates in silk gland development and silk protein synthesis, providing new perspectives for investigating silk gland development and silk protein synthesis mechanisms in silkworms, which is of great significance for selecting and breeding high silk-yielding silkworm varieties.

Overexpression of bond-forming active protein for efficient production of silk with structural changes and properties enhanced in silkworm

Silkworm silk exhibits excellent mechanical properties, biocompatibility, and has potential applications in the biomedical sector. This study focused on enhancing the mechanical properties of Bombyx mori silk by overexpressing three bond-forming active proteins (BFAPs): AFP, HSP, and CRP in the silk glands of silkworms. Rheological tests confirmed increased viscoelasticity in the liquid fibroin stock solution of transgenic silkworms, and dynamic mechanical thermal analysis (DMTA) indicated that all three BFAPs participated in the interactions between fibroin molecular networks in transgenic silk. The mechanical property assay indicated that all three BFAPs improved the mechanical characteristics of transgenic silk, with AFP and HSP having the most significant effects. A synchrotron radiation Fourier transform infrared spectroscopy assay showed that all three BFAPs increased the β-sheet content of transgenic silk. Synchrotron radiation wide-angle X-ray diffraction assay showed that all three BFAPs changed the crystallinity, crystal size, and orientation factor of the silk. AFP and HSP significantly improved the mechanical attributes of transgenic silk through increased crystallinity, refined crystal size, and a slight decrease in orientation. This study opens new possibilities for modifying silk and other fiber materials.

Production and secretion of recombinant spider silk in Bacillus megaterium

BackgroundSilk proteins have emerged as versatile biomaterials with unique chemical and physical properties, making them appealing for various applications. Among them, spider silk, known for its exceptional mechanical strength, has attracted considerable attention. Recombinant production of spider silk represents the most promising route towards its scaled production; however, challenges persist within the upstream optimization of host organisms, including toxicity and low yields. The high cost of downstream cell lysis and protein purification is an additional barrier preventing the widespread production and use of spider silk proteins. Gram-positive bacteria represent an attractive, but underexplored, microbial chassis that may enable a reduction in the cost and difficulty of recombinant silk production through attributes that include, superior secretory capabilities, frequent GRAS status, and previously established use in industry.ResultsIn this study, we explore the potential of gram-positive hosts by engineering the first production and secretion of recombinant spider silk in the Bacillus genus. Using an industrially relevant B. megaterium host, it was found that the Sec secretion pathway enables secretory production of silk, however, the choice of signal sequence plays a vital role in successful secretion. Attempts at increasing secreted titers revealed that multiple translation initiation sites in tandem do not significantly impact silk production levels, contrary to previous findings for other gram-positive hosts and recombinant proteins. Notwithstanding, targeted amino acid supplementation in minimal media was found to increase production by 135% relative to both rich media and unaltered minimal media, yielding secretory titers of approximately 100 mg/L in flask cultures.ConclusionIt is hypothesized that the supplementation strategy addressed metabolic bottlenecks, specifically depletion of ATP and NADPH within the central metabolism, that were previously observed for an E. coli host producing the same recombinant silk construct. Furthermore, this study supports the hypothesis that secretion mitigates the toxicity of the produced silk protein on the host organism and enhances host performance in glucose-based minimal media. While promising, future research is warranted to understand metabolic changes more precisely in the Bacillus host system in response to silk production, optimize signal sequences and promoter strengths, investigate the mechanisms behind the effect of tandem translation initiation sites, and evaluate the performance of this system within a bioreactor.

Knowledge Assessment of Beneficiary Farmers of Technical Service Centres (TSCs) about Recommended Technologies of Sericulture in Karnataka State of India

Sericulture in Karnataka is in the process of modernization in many phases through new demand driven extension approach called Technical Service Centres (TSCs) located at the grass-root level (Hobli and Taluka level). These centres are mainly involved in the dissemination of the technologies developed by the Research Institutes and also in supply of mulberry cuttings/saplings, monitoring mulberry cultivation, silkworm rearing and providing information about loan facilities and subsidy schemes. There is a need to study the attitude of sericulture beneficiary farmers towards activities of TSCs. The study was conducted during 2018-20 in the Karnataka state which contribute 35 per cent of silk production in India. An ex-post facto research design was used or the study. Knowledge test was constructed to measure the knowledge of sericulture farmers on recommended sericulture technologies. The Ramanagara and Mandya districts were selected because these district have highest number of TSCs in Bangalore and Mysore division respectively. Mandya, Malavalli and K.R Pet taluks from Mandya district as well as Ramanagara, Channapatna and Kanakapura taluks from Ramanagara district were selected for the study with four TSCs from each taluk. Totally, 24 TSCs were selected for the study. Ten sericulture farmers under each TSC, collectively 240, were selected by using random sampling method. The study highlighted that more than half (52.50%) and more than one third (36.25%) of the sericulture farmers had medium and high knowledge on recommended technologies of sericulture respectively. Only just more than one tenth (11.25%) of the sericulture farmers had low knowledge on recommended technologies of sericulture. The probable reason might be due to fact that sericulture farmers were regularly consulting from officials of grainage centres, TSC extension functionaries, input dealers and peer group about the information on latest sericulture technologies.

Infestation patterns of a major wood boring pest, Psiloptera fastuosa (Buprestidae: Coleoptera) in Tasar, Terminalia arjuna (Myrtales: Combretaceae) plantation

Tasar silk is a significant cash crop in the tropics. In Tasar culture, arjuna (Terminalia arjuna) (Combretaceae) are often planted on farms because the Tasar worm largely consumes their leaves, Antheraea paphia (Lepidoptera: Saturniidae). The wood-boring Psiloptera fastuosa (Coleoptera: Buprestidae) causes severe threats to Tasar plantations during their mating season (September equinox to December solstice). After hatching, the coleopteran grubs puncture and penetrate the arjuna stem, mature into pupae inside, pass into adults, and exit through emergence holes, causing severe damage to younger plants. Though such infestations are highly fatal, no precautions have been proposed to protect the arjuna plantations. Therefore, sustainable Tasar plantation management is highly challenging because of limited bio-ecological information and the infestation pattern of the pest. This study investigates the origins and implications of P. fastuosa infestations in T. arjuna plantations. Our study focuses on seasonal changes in P. fastuosa assaults on its primary host and infestation frequency in an Indian agroecosystem. Second, we examined whether host plant age and size affected the P. fastuosa invasion. The occurrence and distribution of emergence holes for adult beetles on the arjuna bark and the intensity of wood galleries on the stem aid in assessing the beetle infestation. It was observed that 4 to 8-year-old arjuna plants wilted more frequently than younger (< 4 years) and older (> 8 years) plants. Since most infestations occur on the main trunks up to the middle of the plant's height during autumn, insecticidal treatments can be performed around the middle of the main trunks of 4–8-year-old arjuna plants during fall. The findings of this study will benefit the management and propagation of arjuna plants for tropical Tasar silk production.

Spider Web-Inspired Additive Manufacturing: Unleashing the Potential of Lightweight Support Structures

This paper explores the methodology for the utilization of spider web-inspired additive manufacturing to enhance overhang support structures in 3D printing. Inspired by the strength and flexibility of spider silk, we propose an approach that reduces material consumption and postprocessing efforts. The methodology includes 3D printing spider webs, addressing key questions on silk production, web strength, and printing path generation. Experimental results demonstrate substantial weight reduction in printed objects, showcasing the efficiency of spider web-inspired support compared to traditional methods. The potential applications extend to hollow shell printing and efficient mass production.

Exploring the Relationship between Farmer Characteristics and Training Effectiveness in Sericulture Cultivation

The resurgence of the sericulture industry, driven by the demand for sustainable fibers, necessitates a nuanced understanding of sericulture cultivation practices. This study explores the crucial relationship between farmer characteristics and the effectiveness of training programs in the traditional sericultural districts of Bholahat, Bangladesh, which contribute 75% of the country’s silk production. Using a mixed-methods approach, 192 respondents who underwent sericulture training were surveyed, interviewed, and observed on-site. The research reveals 10 significant and 9 non-significant characteristics out of 19, vital for understanding training effectiveness. The study delves into the link between farmer characteristics and training effectiveness, aiming to identify factors shaping perceptions. Insights gained contribute to designing targeted training programs for sericulture farmers, enhancing overall impact, and improving cultivation practices. The research also highlights key demographic factors, providing a comprehensive understanding of sericulture farmers and guiding informed decision-making in development and training strategies.

Insecticide use in mulberry pest management and its combined effects on silk productivity

Insecticide use in mulberry pest management and its combined effects on silk productivity

Socio-Economic Problems and Challenges Faced by Sericulture Farmers in Karnataka: A Sociological Study

Silk production as an art and science referred to as sericulture is documented to be of very ancient origin in India. Records indicate that it is one of the oldest countries where silk farming and weaving were done. Indications are that in its first ever practice in the world, sericulture can be traced back to 2450 B.C during the Indus Valley Civilization period in India. Still, silk farmers in Karnataka deal with a bunch of social and economic problems. Growing silkworms to make silk has been a job people in Karnataka have done for ages helping many country families make a living. Even though it can bring in money, silk farmers run into several issues that make it hard for them to stay stable and do well in life. The researcher has used questionnaire method to collect data about the prevailing conditions of the sericulture farmers in Karnataka. The economic conditions are the main issue and needs to be addressed from all stakeholders.This paper shall try to bring out these challenges and gives solutions to improve the conditions of sericulture farmers.