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Since the couple of decades the demand for silk has been increasing day by day but the average silk production is not enough to meet its demand. In this study, we investigated the effect of with Maize extract in different concentration (0.5%,1.0 %,1.5 %,2.0%, 2.5 %)on the growth 5th stage silkworm larvae on the biological and commercial traits of Bombyx mori L. The silkworm larvae at 5th instar stage were taken and fed with fresh and healthy mulberry leaves coated with Maize extract in different concentration. Results of the current study revealed that the higher growth parameters of 5th stage silkworm larvae, the cocoon weight, shell weight, and shell ratio were increased, and thus improved the quality of silk as compared to the control. The commercial traits of larvae fed with Maize extract in different concentration leaves also improved significantly. The larvae fed with Maize extract in different concentration treated mulberry leaves showed the maximum cocoon weight, cocoon length, cocoon width, cocoon shell ratio and fibroin content as compared to the control group. It is evident from the results that the fed with Maize extract coated mulberry leaves have a positive effect on the commercial and biological traits of Bombyx mori (L.). [ABSTRACT FROM AUTHOR]

Over the past two decades, significant advancements have been made in the scalable production and commercialization of microbially‐produced recombinant protein polymers. This perspective presents the evolution from early research efforts to the development of market‐ready products, with a focus on recombinant silk‐like proteins. Initial attempts to synthesize spider silk proteins in microbial hosts faced challenges with solubility, stability, and yield. Recent advancements in synthetic biology, protein engineering, and bioprocess development have enabled the substantial progress on these challenges. Early commercial efforts highlight the complexities and high costs involved in silk production and more recent strategies have shifted toward processes with better scalability, techno‐economics, and product properties. Significant commercial progress has been made, with products launched in textiles and personal care. Although market penetration is limited so far, substantial groundwork is laid for future success. Key challenges remain, such as continued high production costs and the need for cost‐effective purification and fiber spinning techniques. However, the convergence of scientific, technological, and market developments –including a growing number of product launches – suggests that recombinant silk and protein polymers can soon become widespread sustainable materials across various industries. [ABSTRACT FROM AUTHOR]

Considering that sericulture is an important branch of animal husbandry, not only for the production of silk but also as a valuable source of protein, it is necessary to constantly study the possibilities for its improvement as a branch of this domain. Therefore, the purpose of this paper is to assess the nutritional value and digestibility of mulberry leaves from the Kokuso 21 and Eforie varieties, as consumed by silkworms (Bombyx mori L., Bombicidae Family, Lepidoptera Order) during a summer study, in 2021. The Japanese variety (Kokuso 21) and the Romanian variety (Eforie) were used as food sources for the Triumf hybrid, developed in Romania; the larvae were divided in two batches of 300 larvae and each set was subdivided into six groups of 50 larvae, which were raised in paper trays based on their age and size. The research indicated that mulberry leaves have an average digestibility value of 54.46%; the aging process of the leaves altered their chemical composition, with most nutrients showing a decreasing trend in digestibility throughout the larval growth period, except for crude fiber, which remained unchanged in the early larval stages and increased to 26.78% towards the end of the experiment. Overall, the Kokuso 21 variety demonstrated superior nutrient digestibility compared to Eforie. An important finding from this study is the need for future research to determine the degree of nutrient metabolism and conversion into silk. [ABSTRACT FROM AUTHOR]

We present the first long-read de novo assembly and annotation of the luna moth (Actias luna) and provide the full characterization of heavy chain fibroin (h-fibroin), a long and highly repetitive gene (>20 kb) essential in silk fiber production. There are >160,000 described species of moths and butterflies (Lepidoptera), but only within the last 5 years have we begun to recover high-quality annotated whole genomes across the order that capture h-fibroin. Using PacBio HiFi reads, we produce the first high-quality long-read reference genome for this species. The assembled genome has a length of 532 Mb, a contig N50 of 16.8 Mb, an L50 of 14 contigs, and 99.4% completeness (BUSCO). Our annotation using Bombyx mori protein and A. luna RNAseq evidence captured a total of 20,866 genes at 98.9% completeness with 10,267 functionally annotated proteins and a full-length h-fibroin annotation of 2,679 amino acid residues. [ABSTRACT FROM AUTHOR]

The silkworm is an economically important insect known for its unique silk production. Oviposition is an important aspect of insect reproduction which needs in-depth study. The aim of this study was to determine the effect of the mating period on the fecundity, egg fertility, and performance of bivoltine silkworm (Bombyx mori L). Adult males and females were allowed to mate for 1, 2, 3, 4, 5, and 6 hours respectively. The eggs laid by the mother moth were acid treated, incubated, and subsequent hatched larvae were reared following standard protocols. The treatments were replicated five times and placed in a completely randomized design. Data were collected on female fecundity, egg fertility, larval and pupal weights, larval survival, and cocoon parameters. Data were subjected to analysis of variance and means were separated using DMRT (P <0.05). The results showed that the number of eggs laid, larval weight, number of cocoons harvested, shell ratio, and effective rate of rearing were significantly higher in progeny whose parents were allowed to mate for one hour. The cocoon weight, pupal weight, and shell weight were highest in progeny whose parents were allowed to mate for five hours, but not significantly different from the ones of other mating durations. There was a negative linear relationship between mating duration and hatchability (r=-0.88) at P<0.05. The study conclusively established that mating duration of one hour in bivoltine silkworms is enough to produce the best larval and cocoon performance. Hence, one-hour mating duration can be recommended for silkworm producers in the sericulture industry. [ABSTRACT FROM AUTHOR]

Animal silk is economically important, while silk secretion is a complex and subtle mechanism regulated by many genes. We identified the poly (ADP‐ribose) polymerase (PARP1) gene of the silkworm and successfully cloned its coding sequence (CDS) sequence. Using clustered regularly interspaced short palindromic repeat (CRISPR/Cas9) technology, we screened single guide RNA (sgRNA) with high knockout efficiency by cellular experiments and obtained PARP1 mutants by knocking out the PARP1 gene of the silkworm at the individual level. We found that the mutants mainly exhibited phenotypes such as smaller cocoon size and reduced cocoon shell rate than the wild type. We also detected the expression of silk protein genes in the mutant by quantitative real‐time PCR (qPCR) and found that the expression of some silk protein genes was slightly down‐regulated. Meanwhile, together with the results of transcriptomic analysis, we hypothesized that PARP1 may affect the synthesis of silk proteins, resulting in their failure to function properly. Our study may provide an important reference for future in‐depth refinement of the molecular mechanism of silk protein expression in silk‐producing animals, as well as a potential idea for future development of molecular breeding lines of silkworms to improve silk production. [ABSTRACT FROM AUTHOR]

Insect silks possess excellent biodegradability, biocompatibility and mechanical properties, and have numerous applications in biomedicine and tissue engineering. However, the application of silk fiber is hindered by its limited supply, especially from non‐domesticated insects. In the present study, the silk yield and organ size of Bombyx mori were significantly improved through genetic manipulation of the target of rapamycin complex 1 (TORC1) pathway components. Silk protein synthesis and silk gland size were decreased following rapamycin treatment, inhibiting the TORC1 signaling pathway both in vivo and ex vivo. The overexpression of posterior silk gland‐specific Rheb and BmSLC7A5 improved silk protein synthesis and silk gland size by activating the TORC1 signaling pathway. Silk yield in BmSLC7A5‐overexpression silkworms was significantly increased by approximately 25%. We have demonstrated that the TORC1 signaling pathway is involved in the transcription and translation of silk genes and transcriptional activators via phosphorylation of p70 S6 kinase 1 and 4E‐binding protein 1. Our findings present a strategy for increasing silk yield and organ size in silk‐producing insects. [ABSTRACT FROM AUTHOR]

Bombyx mori nucleopolyhedrovirus (BmNPV) is a pathogen causing Bombyx mori larval mortality and is also called grasserie disease (Lepidoptera: Bombycidae). Since this viral disease is not fully under control in sericulture, it is necessary to identify agents that can prevent or reduce the infection/proliferation of BmNPV in B. mori culture boxes. Sericultural activity is similar an agriculture, and the loss of cocoon production leads to economic losses. In this research area, we previously reported that the molecule Bm5 inhibits cathepsin activity from BmNPV (V-CATH) and protects infected B. mori larvae from liquefaction processes, limiting the spread of the disease. Here, we evaluated the efficacy of Bm5 in reducing sericultural loss due to BmNPV infection. Assays were carried out with B. mori fifth-instar hybrids immediately inoculated with BmNPV and Bm5 to prevent viral cathepsin action. The biological and productive variables relevant during larval development and cocoon productivity were analysed to verify the effectiveness of Bm5 treatment. Biological and economic parameter data showed that the larval survival rate of the BmNPV-infected and Bm5-treated groups was 35.6% higher than that of the untreated BmNPV group. In addition, the infected BmNPV and Bm5-treated groups showed surviving pupae that produced good-quality cocoons. The α- and β-esterase analysis from the midgut and fat body did not show a change in isoenzyme expression between Bm5-treated and untreated larvae infected with BmNPV. Therefore, the inhibition of viral cathepsin with the Bm5 was shown to be effective in reducing the loss of silk production from BmNPV-infected B. mori larvae. [ABSTRACT FROM AUTHOR]

Following COVID-19 pandemic, functional foods and beverages continue to develop, especially those with high antioxidant activity. The functional beverage from corn silk can be processed into brewed tea. The critical points in the making process of corn silk tea are the drying equipment, drying temperature, and drying time. With efficient method, corn silk tea can produce high antioxidant activity. The present work optimised the temperature and drying method based on antioxidant activity. The results of the present work are expected to be used in micro/small/medium enterprises (MSMEs) to produce corn silk herbal tea. The present work used Randomised Block Design (RBD) with two factors; drying temperatures (45, 55, and 65°C) and drying equipment (cabinet and oven) for 5 h. The analysis carried out was antioxidant activity and profiling using LC-HRMS (liquid chromatography high-resolution mass spectrometry) that ran in a positive (+) mode. The processing of corn silk tea using cabinet drying at 65°C for 5 h produced antioxidant activity of 82.00 ± 0.75%. This was higher than commercial black tea (81.71 ± 0.15%) and commercial green tea (78.37 ± 0.43%). The analysis using LC-HRMS showed that the corn silk tea contained betaine (N,N,N-trimethylglycine) (RT 0.928), 6-methylquinoline (RT 4.741), hesperidin (3’,5,7-trihydroxy-4’-methoxyflavanone) (RT 302.07817), luvangetin (10-methoxy-2,2-dimethylpyrano[3,2-g]chromen-8-one) (RT 258.08837), embelin (2,5-dihydroxy-3-undecyl-1,4-benzoquinone) (RT 13.074), and eucalyptol (1,8- cineole) (RT 13.325). [ABSTRACT FROM AUTHOR]

Sericulture, the practice of rearing silkworms for the production of silk, is an essential agro‐based industry in several countries. However, silkworms are susceptible to a variety of diseases caused by viruses, bacteria and parasites, which may have a significant negative impact on global silk production. Traditional methods of pathogen identification, such as microscopy and laboratory culturing, have limitations in terms of accuracy and efficiency. The development of molecular techniques for pathogen identification has revolutionised the field of sericulture over the last decade. Genomic DNA and RNA‐based molecular techniques allow for the rapid and accurate detection of disease‐causing pathogens in silkworms. Molecular diagnosis has several advantages over traditional methods, including increased sensitivity and specificity, shorter turnaround time and the ability to detect pathogens that are difficult to culture or visualise under a microscope. Molecular techniques have been applied to detect several important pathogens of silkworms, including Nosema sp., nucleopolyhedrovirus, cypovirus, iflavirus and bidensovirus. The use of molecular diagnostics in sericulture is immensely important as the demand for high‐quality silk increases globally and the assessment of emerging pathogens associated with crop loss is essential. Major advancements in the improvement and application of molecular methods for diagnosing widespread silkworm pathogens are discussed. [ABSTRACT FROM AUTHOR]

Cocoons have a direct impact on the quality of raw silk. Mulberry cocoons must be screened before silk reeling can begin in order to improve the quality of raw silk. For the silk product sector, the cocoons' level of categorization and sorting is crucial. Nonetheless, the majority of mulberry cocoon production facilities in use today choose the cocoons by hand. The accuracy and efficiency of mulberry cocoon plucking can be significantly improved by automatic methods. To increase efficiency, mulberry cocoons must be sorted automatically and intelligently using machine vision. We proposed an effective detection technique based on vision and terahertz spectrum characteristics data for distinguishing defective cocoons, including common and thin shelled defective cocoons. Each mulberry cocoon with a defect had its spatial coordinate and deflection angle computed so that grippers could grasp it. With 3762 photos in our dataset, our approach could detect mAP values up to 99.25% of the time. Furthermore, the GFLOPS of our suggested model was only 8.9 G, and its Parameters were only 5.3 M, making it appropriate for use in real-world application scenarios. [ABSTRACT FROM AUTHOR]

Simple Summary: Silkworms are monophagous insects that primarily feed on mulberry leaves. However, in sericulture, cost-effective artificial diets are often used to maximize productivity, which can lead to dietary stress, delayed development, and reduced silk quality in silkworms. Improving silkworms' adaptability to artificial diets is crucial for the sericulture industry. This study aimed to identify key intestinal bacteria taxa that facilitate silkworms' adaptation to dietary transitions by comparing the gut microbiomes of silkworms reared on three different diets: exclusive mulberry leaves, exclusive artificial diet, and a sequential transition from artificial diet to mulberry leaves. Using advanced sequencing techniques and bioinformatic analyses, we discovered that the transitional diet group harbored an intermediary gut microbiota complexity, with specific bacterial groups, such as Lactobacillus and Weissella, potentially aiding in the adaptation process. Our findings provide valuable insights into the adaptation mechanisms of silkworm gut microbiota in response to dietary changes. These results pave the way for developing tailored probiotic supplements that can be added to artificial diets, enhancing silkworms' adaptability and overall health without altering the diet composition. This research holds promise for optimizing sericulture practices, improving silk quality, and ensuring the sustainability of the silk industry. The gut microbiome significantly influences the health and productivity of silkworms (Bombyx mori), the cornerstone of sericulture. With the increasing use of cost-effective artificial diets in sericulture, it is crucial to understand how these diets impact the silkworm gut microbiomes. Here we employed 16S rRNA sequencing to delineate the impact of three distinct dietary regimens on the silkworm gut microbiomes: exclusive mulberry leaf diet (SY), exclusive artificial feed diet (SL), and a sequential transition from artificial feed to mulberry leaves (ZS). Our results unveiled stark differences in microbial diversity across the groups, with the ZS group displaying an intermediary complexity. LefSe and random forest analyses identified Methylobacteriaceae, Microbacterium, and Rhodococcus as significantly enriched in the ZS group, suggesting their potential to facilitate silkworms' adaptation to dietary transitions. Functional profiling revealed differential pathway regulation, indicating a metabolic reconfiguration in response to dietary modulations. Notably, the enrichment of Lactobacillus and Weissella in both the SL and ZS groups highlights their potential as probiotics in artificial diets. Our findings provide insights into the diet adaptation mechanisms of silkworm gut microbiota, paving the way for harnessing the intestinal bacteria to enhance silkworm health and silk production through targeted microbial interventions in sericulture practices. [ABSTRACT FROM AUTHOR]

The study was conducted in Shebadino, Tula and Wondogenet districts of Sidama regional state of southern Ethiopia from 2018 to 2023 with the objectives of to evaluate the performance of silk production technologies at various levels of silk production with stakeholders/beneficiaries. The study also aimed to create awareness and develop confidence among silkworm producers, development agents, agricultural experts and policy makers for wider dissemination. Nine kebeles’ (the lowest administrative level), were selected from three (3) districts for the purposes of this study. Five (5) farmers from each kebele were selected, totaling 45 farmers, for technology pre-scale up and promotion. Three rounds of theoretical and practical training were given to these farmers after they were selected. Training in the third round focused on managing row silk and cocoons after harvest, with a first round that covered broad knowledge and the importance of sericulture. Of the farmers who were chosen and trained, 95.6 percent were women who began raising silk worms, producing cocoons, and processing row silk. Each farmer received 30 kilograms of castor seed and 50 disease-free adult moths for pre-scaling up and promotion of the technology. During the first year of the study period, 90%, 50%, and 40% of the disease-free moths that were disseminated laid eggs and developed into cocoons at Shebadino, Tula sub city and Wondogenet districts respectively. Sericulture is very beneficial to young people, particularly women, in terms of providing a variety of employment options and viable income without affecting their regular agricultural activities or the existing sociocultural equilibrium. Sericulture technology with its package used, knowledge and skill of the farmers (users) on the technology upgraded, continuous follow up assured by DAs and experts. This study highlights the significance of sericulture for rural development and offers insightful information for its dissemination. [ABSTRACT FROM AUTHOR]

The purpose of this research was to identify the main tendencies in raw silk trade at the global level and in the EU main producing and trading countries like China and India in Asia, and Italy, France, Romania, Germany and Spain in the EU. To attain this goal, the data referred to the last decade divided into two sub-periods 2013-2017 and 2018-2022 for allowing the comparison and quantification of the differences. The methodological procedures included the use of fixed basis indices, absolute and relative differences among sub-periods, comparison, trend regression equations and R square served as statistical tools to process the data from ITC and OEC World. The results pointed out the decline by 43.2% in world raw silk production which attained 91 thousand MT in 2022 vs 2013. The global raw silk export decreased from USD 3.12 Billion in 2013 to USD 1.91 Billion in 2022 (-38.8%), while the import went down by 38.8% from USD 2.41 Billion to USD 1.65 Billion (-31.54%). In consequence, trade balance remained positive at USD 0.26 Billion in 2022, but being 2.5 times smaller than in 2013. In the EU, in 2022, raw silk export was USD 0.46 Billion (-46.5% lower vs 2013), while import value attained USD 0.62 Billion (- 37.4% vs 2013), resulting a negative balance of - USD 0.16 Billion. China maintained its top position as a silk producer and exporter, with a positive trade balance, but negative in 2020-2022. The Asian competitors India, Uzbekistan and Vietnam increased production and their trade as well. The EU is a very important raw silk importer, so that its trade balance is negative (-USD 0.16 Billion in 2022). Italy is a remarkable top silk importer in the world, and France, Romania, Germany and Spain are also representatives. Silk textiles remain of high attraction for fashion industry, a reason to expect as production and commerce to flourish in the future, as in the EU is a new orientation to reduce the wastes caused by fast fashion based on synthetic fibers and to encourage the production of healthier and environment friendly natural fibers like silk which has to sustain fashion, textile and apparel industries. [ABSTRACT FROM AUTHOR]

Articles and studies on medieval subjects featured prominently in the pages of Études balkaniques between 2014 and 2023. Conventionally they are divided into two larger groups, according to their focus on issues related to Byzantine and Bulgarian history. This overview begins with an outline of the studies relevant to the development of medieval Bulgaria. This category comprises the works of medievalists such as Vassilka Tâpkova-Zaïmova, Penka Danova, Sashka Georgieva, etc. Elena Kostova's article on the possessions of the Athonite monasteries in the present-day Bulgarian town of Melnik also belongs to this set of themes as it throws a natural bridge to the extensive thematic range of Byzantine studies. Among the examined studies in this field are papers dedicated to the graffiti in the Constantinople Cathedral of Hagia Sophia, Byzantium's ties to Southern Italy and Egypt, silk production, the empire's political relations with its neighbours such as the community of the Cumans and other themes from the history of what came to be known as the "Byzantine cultural circle", whose geographical reach extended up to the Caucasus and Russia. The overview ends with a discussion of two articles by Theodor Dimitrov, which examine the plague epidemics in Byzantium. [ABSTRACT FROM AUTHOR]

Tamarisk is an invasive evergreen shrub native to arid regions of Africa and Eurasia and is considered a weed in some countries with dry climates. The complex of gall mites from tamarisks includes fourteen species from four genera of the family Eriophyidae. We reinvestigated the type species of the genus Dicruvasates, D. tamaricis from Egypt, described D. ngubani n. sp. from Tamarix usneoides from South Africa, and revised the generic concept of Dicruvasates. This genus possesses cuticular plates marking longitudinal opisthosomal ridges typical of various phyllocoptine genera, e.g., Echinacrus. We sequenced three genes of Dicruvasates and Phyllocoptes mites from Tamarix and Echinacrus from Frangula, combined our sequences with the data from GenBank, and performed single-gene phylogenetic analyses. All analyses inferred the following: (1) a transcontinental clade Tam comprising Dicruvasates + Aceria + Phyllocoptes from Tamarix; (2) Echinacrus distantly related to Dicruvasates, suggesting the homoplastic nature of the cuticular plates on the opisthosomal ridges, and (3) polyphyly of the genera Aceria and Phyllocoptes. We also investigated partially cleared specimens of Dicruvasates under CLSM and, for the first time, visualized a well-developed anal secretory apparatus (ASA) in the immatures of gall mites, which was previously shown to be a specialized system evolved in Eriophyoidea for silk production. We hypothesize that the ASA contributes to finding nymphs by conspecific males and advocate for the importance of the future molecular biology studies of gall mite silk for developing new methods for controlling mites based on the knowledge of their ecology, behavior, and silk gene genetics. [ABSTRACT FROM AUTHOR]

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 BmSGF1 G4−/− 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. [ABSTRACT FROM AUTHOR]

One of the earliest fibers used by mankind is silk, which was first cultivated in China. Mulberry silk is produced from Bombyx Mori which feeds on mulberry tree leaves. Bombyx Mori silkworm, hatching from its egg after 8–10 days of incubation, starts spinning its cocoon around itself on the 25th or 28th day. These cocoons are subjected to dry heat or boiling water which kills the pupae. Most of the silk consumers in Turkey are not aware of the fact that the silkworms are killed before completing their natural life span. On the other hand, the number of consumers has been rising in the world who wants to wear silk without harming the animals. In this study sericulture was done in an ethical way to produce peace silk fabrics and some of the mechanical properties of the fabrics were determined. This study is of value, raising awareness about peace silk and ethical production. [ABSTRACT FROM AUTHOR]

Diet plays a crucial role in shaping the gut microbiota and overall health of animals. Traditionally, silkworms are fed fresh mulberry leaves, and artificial diets do not support good health. The aim of this study was to explore the relationship between the dietary transition from artificial diets to mulberry leaves and the effects on the gut microbiota and physiological changes in silkworms as a model organism. With the transition from artificial diets to mulberry leaves, the diversity of the silkworm gut microbiota increased, and the proportion of Enterococcus and Weissella, the dominant gut bacterial species in silkworms reared on artificial diets, decreased, whereas the abundance of Achromobacter and Rhodococcus increased. Dietary transition at different times, including the third or fifth instar larval stages, resulted in significant differences in the growth and development, immune resistance, and silk production capacity of silkworms. These changes might have been associated with the rapid adaptation of the intestinal microbiota of silkworms to dietary transition. This study preliminarily established a dietary transition–gut microbial model in silkworms based on the conversion from artificial diets to mulberry leaves, thus providing an important reference for future studies on the mechanisms through which habitual dietary changes affect host physiology through the gut microbiome. [ABSTRACT FROM AUTHOR]

Background: Silk 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. Results: In 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. Conclusion: It 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. [ABSTRACT FROM AUTHOR]

The silk-spinning process of the silkworms transforms the liquid silk solution to a solid state under mild conditions, making it an attractive model for bioinspiration However, the precise mechanism behind silk expulsion remains largely unknown. Here we selected the silkworms as representative models to investigate the silk-spinning mechanism. We used serial block-face scanning electron microscopy (SBF-SEM) to reconstruct the three-dimensional structures of the spinnerets in silkworms at various stages and with different gene backgrounds. By comparing the musculature and duct deformation of these spinneret models during the spinning process, we were able to simulate the morphological changes of the spinneret. Based on the results, we proposed three essential factors for silkworm spinning: the pressure generated by the silk gland, the opening duct, and the pulling force generated by head movement. Understanding the silkworm spinning process provides insights into clarify the fluid-ejecting mechanism of a group of animals. Moreover, these findings are helpful to the development of biomimetic spinning device that mimics the push-and-pull dual-force system in silkworms. The silkworms' spinning system produces fibers under mild conditions, making it an ideal candidate for bioinspiration. However, the mechanism of silk expulsion is unknown, and the three-dimensional structure of the spinneret is still uncertain. In this study, we reconstructed a detailed 3-dimensional model of the spinneret at near-nanometer resolution, and for the first time, we observed the changes that occur before and during the silk-spinning process. Our reconstructed models suggested that silkworms have the ability to control the spinning process by opening or closing the spinning duct. During the continuously spinning period, both the pressure generated by the silk gland and the pulling force resulting from head movement work in tandem to expel the silk solution. We believe that gaining a full understanding of the spinning process steps can advance our ability to spin synthetic fibers with properties comparable to those of native fibers by mimicking the natural spinning process. [Display omitted] [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the dynamics of raw silk production in the period 2011-2022 at the global level and in the top six producing countries using the official data and usual methods in such a research: fixed basis and structural indices, descriptive statistics, regression equations, coefficient of determination, correlations, absolute and relative differences, comparisons etc. The results showed that, at the global level, raw silk production accounted for 91,221 Metric tons in the year 2022 being by 30% smaller than in 2011. The top silk producing countries are China, India, Uzbekistan, Vietnam, Thailand and Brazil. While in China, Thailand and Brazil production has substantially declined (- 52%, -33.5%, -23%), in India, Uzbekistan and Vietnam silk production increased by 58.6%, 116.7% and 113.4%. The share of all these six countries in the global production is 99.2%. In 2022, the highest weight belongs to China (54.8%) and India (40.1%). It is expected as silk production to raise taking into account that it is an eco and skin friendly product, and also a biodegradable product, while synthetic fibers are polluting. However, the high production cost, market price fluctuation and other restraining factors could affect small farmers dealing with sericiculture. For the developing countries, silkworm rearing and silk production sector is a profitable business which offer jobs, income, a better living standard, reducing poverty, hungry, gender discrimination, preserving biodiversity and conserving soil quality and contributing to the sustainable development in the rural areas. [ABSTRACT FROM AUTHOR]

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The process of drum drying silk has complex characteristics of multivariability, strong coupling, and nonlinearity. Traditional Principal Component Analysis (PCA) method lacks strong nonlinear ability, and global modeling method is difficult to achieve accurate fault detection of the process. Therefore, this paper proposed a novel multi-block approach by integrating Autoencoder (AE) for feature extraction and PCA model. Initially, in order to capture local features, the process variables were divided into blocks according to the drying process principle of tobacco leaf. Secondly, autoencoder was used to extract the nonlinear features of each sub-block. Then, the corresponding PCA models are established for each sub-block, respectively. Lastly, the monitoring results of multiple subspaces were fused for decision-making by Bayesian inference. Two actual leaf silk drying cases were used for verification, and the results showed that the alarm rates of this method were as high as 91.67% and 98.21%. Compared to traditional PCA and AE-PCA detection methods, this algorithm could accurately reveal and characterize the overall operating status and local feature information of the drying process, improve the accuracy of anomaly detection in the drum leaf silk drying production process and achieve accurate alarm for quality anomalies, to ensure stable production of the drum leaf silk drying process. [ABSTRACT FROM AUTHOR]

Spiders represent an evolutionary successful group of chelicerate arthropods. The body of spiders is subdivided into two regions (tagmata). The anterior tagma, the prosoma, bears the head appendages and four pairs of walking legs. The segments of the posterior tagma, the opisthosoma, either lost their appendages during the course of evolution or their appendages were substantially modified to fulfill new tasks such as reproduction, gas exchange, and silk production. Previous work has shown that the homeotic Hox genes are involved in shaping the posterior appendages of spiders. In this paper, we investigate the expression of the posterior Hox genes in a tarantula that possesses some key differences of posterior appendages compared to true spiders, such as the lack of the anterior pair of spinnerets and a second set of book lungs instead of trachea. Based on the observed differences in posterior Hox gene expression in true spiders and tarantulas, we argue that subtle changes in the Hox gene expression of the Hox genes abdA and AbdB are possibly responsible for at least some of the morphological differences seen in true spiders versus tarantulas. [ABSTRACT FROM AUTHOR]

Mulberry silkworm is more sensitive to any infection during the rearing season. Maintaining a healthy larva was the main target of this research to lower the probability of infection with microbes besides increasing silk production. There was evidence-based efficacy suggesting that Echinacea purpurea can help to improve immune system barriers by increasing the activity of antioxidant enzymes such as Peroxidase and Phenol oxidase, which boosts silk production. The present investigation was carried out to study the impact of Echinacea purpurea on some biological and biochemical parameters. Silkworm larvae reared on mulberry leaves enriched with different concentrations of Echinacea purpurea (0.5%, 1%, and 2%) at the beginning of the 4th instar till the spinning stage. The obtained results indicated that the feeding larvae on 2% concentration of Echinacea purpurea extract increases, all the economic and biological characteristics also, most of the biochemical parameters (total protein, peroxidase activity, and phenoloxidase). while larvae fed at 1% concentration recorded high ascorbic acid values. [ABSTRACT FROM AUTHOR]

Silk fibroin is a natural, protein-based biopolymer produced by silkworm and obtained from silkworm cocoons. It has such features as biocompatibility, biodegradability, high mechanical resistance, low immunogenicity and low inflammatory response. Owing to these properties, it attracts attention in various fields including tissue engineering and drug delivery. The silk fibroin production method basically consists of processes such as degumming, extraction, dialysis, centrifugation, and, if necessary, lyophilization. Since the production of silk fibroin from cocoons includes many steps, there are various parameters that affect the protein content of silk fibroin. In this study, it was aimed to validate the production process steps which mainly affect the silk fibroin content and to determine optimum parameters to obtain silk fibroin with higher protein content. For this purpose, the effects of the type of extraction agent (Ajisawa's reagent or lithium bromide), the molecular weight cutoff value (MWCO) of the dialysis membrane, the dialysis time, and the centrifugation process were evaluated statistically with one-way analysis of variance method. According to the results, the highest protein content is obtained using, LiBr as extraction agent, 3500 Da as MWCO value of dialysis membrane, 2 days as dialysis time and 532 RCF for 5 min as conditions of centrifugation process. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal Production & Processing Technology / JurnalIlmu Produksi dan Teknologi Hasil Peternakan is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Silk degumming is considered the first point in the preparation of silk-based materials since this process could modify the silk fiber and the properties of its related products. This study evaluated the differences in morphology, secondary structure, amino acid content, thermal stability, and mechanical properties of two types of raw materials, defective cocoons (DC) and silk fibrous waste (SW), degummed by chemical (C) and autoclaving (A) methods. Subsequently, silk fibroin films were prepared by dissolving each type of degummed fibers, and thermal and structural films properties were determined. The findings demonstrated that autoclaving is an efficient alternative to remove silk sericin, as the resulting fibers presented improved structural, thermal, and mechanical properties compared to those obtained by the chemical method. For films preparation, autoclave resulted in a good option, but dissolution parameters need to be adjusted for defective cocoons. Furthermore, similarities between the physicochemical properties of fibers and films from both fibrous wastes suggest that SW is a promising raw material for producing fibrous resources and regenerated silk fibroin materials. Overall, these findings suggest new recycling methods for fibrous waste and by-products generated in the silk textile production process. [ABSTRACT FROM AUTHOR]

Simple Summary: Various signals are used in insects to identify mates. Signals based on visual, acoustic, or chemical communication play an important role in sexual selection. Frequently occurring chemical-based signals are the most important and understudied field of communication. Spiders use a wide variety of chemicals to find potential mates, but, until now, only a few spider-used pheromones have been identified. The nursery-web spider, Pisaura mirabilis, does not build a typical net, but leaves draglines on the ground. In our research, we investigated the role of chemical signals in female draglines influenced by factors such as spider ontogeny, nutritional status, and female mating status. Our findings indicate that the chemical signals of eggsac-carrying females were similarly sexually attractive to females not carrying eggsac. Draglines of adult and hungry females functioned, in contrast, as stimulation for male motivation to invest more silk in gift production. Chemical differences in female draglines were identified, but they did not always correspond with male behavior. We suggest the integration of behavioral and chemical approaches to better understand animal behavior in future research. Chemical signals used by animals to attract the opposite sex are well known in insects, but heavily understudied in spiders. We investigated the role of chemical signals in female draglines in a gift-giving spider, Pisaura mirabilis, using combined data from behavioral tests and high-performance liquid chromatography (HPLC). We also investigated whether the quality of sexual signalization is influenced by crucial factors, such as female spider ontogeny, nutritional status, and mating status. We found that draglines of adult (versus subadult) and hungry (versus fed) females stimulated male motivation to produce nuptial gift, and highly sexually excited males invested more silk in gift production than less sexually excited males. Unexpectedly, chemical signals of eggsac-carrying females were similarly sexually attractive to draglines of adult females not carrying eggsac. HPLC identified significant chemical differences in female draglines, but these differences did not always correspond to male behavior. The integration of behavioral and chemical approaches is required to better understand animal behavior in future research. [ABSTRACT FROM AUTHOR]

The eighteen (18) F1 hybrid combinations were tested to identify potential combinations adaptable to type 1 climatic conditions in the Philippines. The six (6) bivoltine purelines (DMMMSU 108, DMMMSU 109, DMMMSU 110, DMMMSU 111, DMMMSU 113, and DMMMSU 119); and three (3) multivoltine purelines (DMMMSU 1000, DMMMSU 1007, and DMMMSU 1014), were crossed (multivoltine x bivoltine) in a mating plan. These were arranged in a Completely Randomized Design (CRD), replicated three times, and analyzed using Analysis of Variance (ANOVA). A test of significance was done using ANOVA across years and Tukey's Honest Significant Difference Test (HSD). The multiple trait evaluation index (EI) method was also used in the identification of potential F1 hybrids. Three major phases were done: (1) parental rearing of multivoltine and bivoltine pure lines for breed multiplication; (2) hybridization process; and (3) evaluation of F1 hybrids. Rearing evaluations were conducted for three consecutive years. Based from the three evaluations, 10 potential crosses were identified: DMMMSU MV-12, DMMMSU MV-11, DMMMSU MV-13, DMMMSU MV-16, DMMMSU MV-07, DMMMSU MV-14, DMMMSU MV-05, DMMMSU MV-09, DMMMSU MV-03, and DMMSU MV-10. The topmost combinations with the best economic and commercial characters and are consistently adaptable during two (2) cropping seasons were DMMMSU MV-07, DMMMSU MV-12, DMMMSU MV-05, DMMMSU MV-09 and DMMMSU MV-11. These newly-identified F1 hybrids are considered potential breeds that could improve cocoon production. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of cow's milk as a protein supplement to improve growth and expression of productive parameters in the silkworm (Bombyx mori L.). Design/Methodology/Approach: Four treatments with mulberry foliage supplemented with milk were used, plus a control (which was fed with fresh leaf). Feeding was determined for the last two larval instars, resulting in the following groups: Treatment 1: V instar-TD, Treatment 2: V instar-DI, Treatment 3: IV and V instar-TD, and Treatment 4: IV and V instar-DI. Results: Larvae fed with foliage supplemented with milk obtained an increase in growth rate and larval weight and formed their cocoons faster than the control. Additionally, there were differences in cocoon weight, silk percentage, and pupal weight, relevant traits for silk production. Study Limitations/Implications: Very few works have been published about silkworms fed with mulberry foliage supplemented with milk. Findings/Conclusions: Supplementation has a positive effect on growth and the evaluated traits, improving the yield of silk production. [ABSTRACT FROM AUTHOR]

Copyright of Glasnik Zastite Bilja is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spider silk exhibits exceptional strength and elasticity in its natural form. Over the course of several decades, researchers have been working on artificially spinning recombinant spider silk proteins (spidroin) in order to replicate the remarkable mechanical properties of natural spider silk. In this study, we utilized the wet spinning method to investigate the relationship between the concentration of the coagulation bath and fiber performance. We discovered that the concentration of methanol plays a crucial role in determining the continuity, diameter, and mechanical properties of the fibers. Lower concentrations of methanol favor the production of continuous, thinner fibers with higher strain. Additionally, secondary stretching during the spinning process contributes to the production of silk fibers with stable mechanical properties and thermal stability. By employing different concentrations of methanol and applying additional stretching, we successfully produced silk fibers with a high strain of 2.1652 ± 0.3871 mm/mm. Furthermore, these wet-spun fibers demonstrated the ability to promote the growth of Schwann cells, indicating their potential application in the field of biomedical engineering. Hence, the exceptional mechanical properties and the ability to promote cellular growth make the obtained spider silk fibers highly promising for various biomedical applications. [ABSTRACT FROM AUTHOR]

Herbivores have evolved the ability to detoxify feed components through different mechanisms. The oligophagous silkworm feeds on Cudrania tricuspidata leaves (CTLs) instead of mulberry leaves for the purpose of producing special, high-quality silk. However, CTL-fed silkworms are found to have smaller bodies, slower growth and lower silk production than those fed mulberry leaves. Here, we show that the high content of prenylated isoflavones (PIFs) that occurred in CTLs is converted into glycosylated derivatives (GPIFs) in silkworm faeces through the silkworm gut microbiota, and this biotransformation is the key process in PIFs detoxification because GPIFs are found to be much less toxic, as revealed both in vitro and in vivo. Additionally, adding Bacillus subtilis as a probiotic to remodel the gut microbiota could beneficially promote silkworm growth and development. Consequently, this study provides meaningful guidance for silk production by improving the adaptability of CTL-fed silkworms. The silkworm (Bombyx mori) gut microbiome can impact its ability to metabolize and tolerate prenylated isoflavone toxins from plant leaves, providing further insight into how the gut microbiota promotes silkworm growth and development. [ABSTRACT FROM AUTHOR]

The silkworm, which is considered a model invertebrate organism, was the first insect used for silk production in human history and has been utilized extensively throughout its domestication. However, sericulture has been plagued by various pathogens that have caused significant economic losses. To enhance the resistance of a host to its pathogens,numerous strategies have been developed. For instance, gene‐editing techniques have been applied to a wide range of organisms, effectively solving a variety of experimental problems. This review focuses on several common silkworm pests and their pathogenic mechanisms, with a particular emphasis on breeding for disease resistance to control multiple types of silkworm diseases. The review also compares the advantages and disadvantages of transgenic technology and gene‐editing systems. Finally, the paper provides a brief summary of current strategies used in breeding silkworm disease resistance, along with a discussion of the establishment of existing technologies and their future application prospects. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Eri silk produced by silkworm, Samia ricini Donovan is polyphagous in nature and mainly feeds on annual crops (Castor and Tapioca) and perennial trees (Heteropanax fragrans (Roxb.) Seem., Ailanthus sp.). Eri silk is whitish in colour and due to discontinuous fiber filament, it is spun like cotton. As Eri silk is processed without killing the silkworm, it is called as "Ahimsa Silk". Due to higher pupal protein content (150-160 g/kg; 10.3% higher than an edible insect, Acheta domesticus (L.), the eri pupae could be a potential source of protein for human and animal (fish, poultry) consumption. Despite continuous treads in Research and Developmental activities, the vertical expansion of eri silk production has yet to reach expectations and hence, there is a need to explore the non-traditional states to meet the horizontal expansion in eri silk production, especially the castor and tapioca growing areas. This could be possible by developing eri silkworm breeds/hybrids with climate resilience, disease and pest resistance, early and easy disease detection tools, and application of artificial intelligence in pre- and postcocoon sectors. Apart from textile uses, eri silk products are to be explored for non-textile purposes viz., fibroin, sericin, pupae, and pupae oil for cosmetics, nutraceutical, pharmaceutical, and human consumption. The eri silk is found to be a profitable livelihood business enterprise in India. In recent days, the ericulture has been introduced in other parts of the country, but much more effort is needed to make the value chain stakeholder's friendly and economically viable enterprise through product diversification and utilization of by-products. [ABSTRACT FROM AUTHOR]

The Gorgan Plain (NE Iran) is largely treeless today but it possibly was not in the past. We use palaeobotanical data from radiocarbon-dated sediments and archaeological excavations to investigate the extent and use of woodland under the Sasanian Empire (224–651 CE). Palynology, anatomical studies of charred and uncharred wood, insects and botanical macroremains have shed new light on this question. Palynological research points to natural origins of the open steppe vegetation in the Gorgan Plain contrasting to carpological and wood anatomy studies indicating wide use of trees and shrubs during the Sasanian period. As it shown by charcoal data, local sources provided enough firewood for kilns in short-term use, but were insufficient for supplying fortification garrisons which required additional supplies from the Hyrcanian forests. These forests provided the main source of firewood for sites located close to the Alborz Mountains. Cultivation of trees was widespread during the Sasanian era for fruits, shadow and possibly moriculture for silk production. Palaeobotanical records are still very rare in the Gorgan Plain. New data are a desideratum to gain further insights into woodland use before, during and after the Sasanian Empire. [ABSTRACT FROM AUTHOR]

The Indian meal moth (Plodia interpunctella) is becoming an important biological model to study silk. While there are many potential applications to materials science and medicine, many aspects of silk production in this species remain unknown. Here we characterize the silk of P. interpunctella by measuring the width of larval wandering and pupal silk strands and find that the latter is significantly thicker than the former. We also report intraspecific variation in pupal silk production in our lab-reared colony with a very small number of individuals forgoing pupal silk production entirely (< 4%). Overcrowding had no effect on silk formation, but exposure to elevated temperature reduced pupal silk production. [ABSTRACT FROM AUTHOR]

The present study was conducted at the research farm of Regional Agricultural Research Station (RARS), Palem, Telangana State, India during rabi (October–January) seasons of 2012–13 and 2013–14 to exploit the high yielding castor genotypes with respect to scientific ericulture and to know the prospects for its rate of adoption. Amid the eight genotypes of castor, highest 10th day larval weight of 0.645 g, 0.651 g and 0.639 and highest mature larval weight of 6.012 g, 5.982 and 5.948 g was recorded in the eri silkworm reared on PCH-111, PCH-222 and GCH-4 respectively. Enhancement in shell weight (0.981 g) was obtained in the eri silkworm fed on PCH-111 followed by GCH-4 (0.778 g). Significantly highest ERR was recorded in the eri silkworm reared on PCH-111 (92.7%) genotype and PCH-222 (92.23%) with no significant difference among them. The mortality rate of the eri silkworms reared on different castor genotypes ranged between 3.3%–12.08%. Significantly the highest survival rate of 96.15% was recorded in the eri silkworms reared on Haritha genotype followed by PCH-222 (94.06%). The study revealed that nearly 61.25% of the eri rearers exhibited medium level of extent of adoption, followed by 21.25% with low level of extent of adoption, while about 17.50% of the rearers exhibited high adoption respectively with respect to scientific method of ericulture practices. The perusal of the data revealed that out of nine dependent variables, six variables viz, age, educational qualification, size of land holding, family annual income, risk bearing of the rearers and knowledge gained through training were positively and significantly related with the extent of adoption. [ABSTRACT FROM AUTHOR]

Natural fibres are the preferred options for garment, technical and medical textiles, nonwovens and composites. Their sustainability is a considerable advantage, though the nature of silk production and processing involves a large amount of waste. The present review explores the current issues of recycling silk waste into nonwovens for various purposes. The article proposes obtaining nonwovens from short fibres using electrospinning of fibroin solutions in volatile solvents. Longer fibres are proposed to be processed into needle-punched nonwoven materials with a selection of an effective antistatic treatment. [ABSTRACT FROM AUTHOR]

Natural silk fiber derived from the Bombyx mori (B. mori) silkworm has long been used as a luxury raw material in textile industry because of its shimmering appearance and durability, and as surgical suture for its high strength and flexibility. Regenerated silk fibroin, as the main protein extracted from the cocoons of the B. mori silkworm, recently has gained considerable attention due to its outstanding properties, including facile processability, superior biocompatibility, controllable biodegradation, and versatile functionalization. Tremendous effort has been made to fabricate silk fibroin into various promising materials with controlled structural and functional characteristics for advanced utilities in a multitude of biomedical applications, flexible optics, electronics devices, and filtration systems. Herein, reverse engineered silk fibroin extraction methods are reviewed, recent advances in extraction techniques are discussed. Fabrication methods of silk fibroin materials in various formats are also addressed in detail; in particular, progress in new fabrication technologies is presented. Attractive applications of silk fibroin-based materials are then summarized and highlighted. The challenges faced by current approaches in production of silk fibroin-based materials and future directions acquired for pushing these favorable materials further toward above mentioned applications are further elaborated. [ABSTRACT FROM AUTHOR]

To investigate the metabolic elasticity and production bottlenecks for recombinant silk proteins in Escherichia coli , we performed a comprehensive characterization of one elastin-like peptide strain (ELP) and two silk protein strains (A5 4mer, A5 16mer). Our approach included 13C metabolic flux analysis, genome-scale modeling, transcription analysis, and 13C-assisted media optimization experiments. Three engineered strains maintained their central flux network during growth, while measurable metabolic flux redistributions (such as the Entner–Doudoroff pathway) were detected. Under metabolic burdens, the reduced TCA fluxes forced the engineered strain to rely more on substrate-level phosphorylation for ATP production, which increased acetate overflow. Acetate (as low as 10 mM) in the media was highly toxic to silk-producing strains, which reduced 4mer production by 43% and 16mer by 84%, respectively. Due to the high toxicity of large-size silk proteins, 16mer′s productivity was limited, particularly in the minimal medium. Therefore, metabolic burden, overflow acetate, and toxicity of silk proteins may form a vicious positive feedback loop that fractures the metabolic network. Three solutions could be applied: 1) addition of building block supplements (i.e., eight key amino acids: His, Ile, Phe, Pro, Tyr, Lys, Met, Glu) to reduce metabolic burden; 2) disengagement of growth and production; and 3) use of non-glucose based substrate to reduce acetate overflow. Other reported strategies were also discussed in light of decoupling this positive feedback loop. [Display omitted] • 13C MFA was performed to analyze E.coli to produce repetitive silk proteins. • Engineered E.coli shows flux network redistributions (e.g., the TCA cycle and the ED pathway). • Silk protein producers (particularly A5 16mer) are highly sensitive to acetate stresses. • Bioproduction may lead to a positive metabolic feedback loop that limits protein production. • Nutrient supplementation and substrate co-utilization improved bioproduction. [ABSTRACT FROM AUTHOR]

Dimapur (Nagaland, India) is dominated by undifferentiated hillside slopes and alluvial plains. The Muga and Eri silk industries are important cultural and economic activities for the inhabitants of Dimapur. Profitable silk production requires adequate quality and quantity of healthy leaves and is highly dependent on the soil fertility of the region. Keeping this in view, the present study was carried out as a first attempt to prepare a geographic information system (GIS) map for Muga and Eri soils in Dimapur, Nagaland. A total 65 surface (0–15 cm) soil samples from Muga farms and 79 surface soil samples from Eri farms were collected and analysed for soil pH, organic carbon content and availability of macro- and micronutrients. Soils of both Muga and Eri farms were found to be extremely (<3.05) to moderately (5.09–6.84) acidic. Soils of Muga and Eri farms were found to have low to high organic carbon content (from 0.24 to 1.98%), low to high available nitrogen content (179.8–612.5 kg ha−1) and medium available phosphorus content (2.68–154.6 kg ha−1). The sulphur availability index was 0.26 and 11.81 for Muga and Eri host plant farms, respectively. The multi-macronutrient map revealed that 46.95% of the district's total geographical area (TGA) showed deficiencies in one or more macronutrients (high priority zone). Thus, these regions need urgent attention in terms of nutrient management decisions in order to reduce the declining trend of soil fertility and achieve sustainable sericulture production. [ABSTRACT FROM AUTHOR]

As a natural high-performance material with a unique hierarchical structure, silk is endowed with superior mechanical properties. However, the current approaches towards producing regenerated silk fibroin (SF) for the preparation of biomedical devices fail to fully exploit the mechanical potential of native silk materials. In this study, using a top-down approach, we exfoliated natural silk fibers into silk nanofibrils (SNFs), through the disintegration of interfibrillar binding forces. The as-prepared SNFs were employed to reinforce the regenerated SF solution to fabricate orthopedic screws with outstanding mechanical properties (compression modulus > 1.1 GPa in a hydrated state). Remarkably, these screws exhibited tunable biodegradation and high cytocompatibility. After 28 days of degradation in protease XIV solution, the weight loss of the screw was ~20% of the original weight. The screws offered a favorable microenvironment to human bone marrow mesenchymal stem cell growth and spread as determined by live/dead staining, F-action staining, and Alamar blue staining. The synergy between native structural components (SNFs) and regenerated SF solutions to form bionanocomposites provides a promising design strategy for the fabrication of biomedical devices with improved performance. [ABSTRACT FROM AUTHOR]

The silkworm (Bombyx mori) is an important lepidopteran model insect and an industrial domestic animal traditionally used for silk production. Here, we report the genome assembly of an improved Japanese strain Nichi01, in which the cocoon yield is comparable to that of commercial silkworm strains. The integration of PacBio Sequel II long-read and ddRAD-seq-based high-density genetic linkage map achieved the highest quality genome assembly of silkworms to date; 22 of the 28 pseudomolecules contained telomeric repeats at both ends, and only four gaps were present in the assembly. A total of 452 Mbp of the assembly with an N50 of 16.614 Mbp covered 99.3% of the complete orthologs of the lepidopteran core genes. Although the genome sequence of Nichi01 and that of the previously reported low-yielding tropical strain p50T assured their accuracy in most regions, we corrected several regions, misassembled in p50T, in our assembly. A total of 18,397 proteins were predicted using over 95 Gb of mRNA-seq derived from 10 different organs, covering 96.9% of the complete orthologs of the lepidopteran core genes. The final assembly and annotation files are available in KAIKObase (https://kaikobase.dna.affrc.go.jp/index.html) along with a genome browser and BLAST searching service, which would facilitate further studies and the breeding of silkworms and other insects. [ABSTRACT FROM AUTHOR]