Optimization of Extraction and Refining Parameters of Oil from Dotted Gizzard Shad (Konosirus punctatus).

To address the challenges associated with resource inefficiency, low extraction rates, environmental concerns, and high energy consumption in traditional fish oil production from dotted gizzard shad (Konosirus punctatus), a novel approach is needed. This study aimed to develop and evaluate two innovative methods for fish oil extraction and refinement, focusing on their effects on fish oil quality, fatty acid profile, and volatile compound composition throughout the respective processes. The findings of the study revealed that the ethanol-assisted enzymatic extraction method surpassed the conventional enzymatic approach in extraction efficiency, achieving an optimal extraction rate of 74.94% ± 0.45% under optimized process conditions. Moreover, the ethanol-NaOH one-step degumming and deacidification method proved effective in simultaneously removing phospholipids and free fatty acids. Under optimal conditions, a notable reduction in phospholipid content in dotted gizzard shad oil, from 6.80 ± 0.01 mg/g to 1.18 ± 0.01 mg/g, and a substantial decrease in acid value, from 3.31 mg/g to 0.31 mg/g, were observed. In summary, the study analyzed the physicochemical properties, fatty acid composition, and volatile components of fish oil before and after refinement. The refining process was found to preserve the fatty acid composition while efficiently eliminating hydroperoxides and reducing unpleasant odors in the crude oil.

Alleviating Nonproductive Adsorption of Lignin on CBM through the Addition of Cationic Additives for Lignocellulosic Hydrolysis.

The nonproductive adsorption of cellulase onto lignin significantly inhibited the enzymatic hydrolysis of lignocellulosic biomass. In this study, we constructed a rapid fluorescence detection (RFD) system, and using this system, we demonstrated that the addition of cationic additives DTAB or polyDADMAC greatly increased the partition coefficients of cellulose/lignin, reduced nonproductive adsorption, and enhanced the hydrolysis efficiency of lignocellulose compared to those of Tweens or PEGs. Moreover, the addition of polyDADMAC and DTAB increased the glucose yield released from the mixture of Avicel and AICS-lignin (MCL) by 16.9 and 20.6%, respectively, and reduced the inhibition rate of lignin by 16.9 and 20.7%, respectively. Interestingly, polyDADMAC or DTAB treatment performed more effectively for the enzymatic hydrolysis of pretreated lignocellulosic biomass, compared with MCL. We confirmed that the reduced hydrophobicity and increased zeta potential of lignin cocontribute to the dampening nonproductive adsorption of lignin. In particular, the zeta potential values of lignin and the partition coefficients of Avicel/lignin with the addition of additives showed a good correlation, suggesting that electrostatic force also plays a crucial role in the adsorbing of cellulase on lignin. This work will be conducive to decreasing the nonproductive binding of cellulase onto lignin and enhancing cellulose conversion.

Role of Trichoderma reesei mitogen-activated protein kinases (MAPKs) in cellulase formation.

BACKGROUND: Despite being the most important cellulase producer, the cellulase-regulating carbon source signal transduction processes in Trichoderma reesei are largely unknown. Elucidating these processes is the key for unveiling how external carbon sources regulate cellulase formation, and ultimately for the improvement of cellulase production and biofuel production from lignocellulose. RESULTS: In this work, the role of the mitogen-activated protein kinase (MAPK) signal transduction pathways on cellulase formation was investigated. The deletion of yeast FUS3-like tmk1 in T. reesei leads to improved growth and significantly improved cellulase formation. However, tmk1 deletion has no effect on the transcription of cellulase-coding genes. The involvement of the cell wall integrity maintenance governing yeast Slt2-like Tmk2 in cellulase formation was investigated by overexpressing tmk3 in T. reesei Δtmk2 to restore cell wall integrity. Transcriptional analysis found little changes in cellulase-coding genes between T. reesei parent, Δtmk2, and Δtmk2::OEtmk3 strains. Cell wall integrity decreased in T. reesei Δtmk2 over the parent strain and restored in Δtmk2::OEtmk3. Meanwhile, cellulase formation is increased in T. reesei Δtmk2 and then decreased in T. reesei Δtmk2::OEtmk3. CONCLUSIONS: These investigations elucidate the role of Tmk1 and Tmk2 on cellulase formation: they repress cellulase formation, respectively, by repressing growth and maintaining cell wall integrity, while neither MAPK regulates the transcription of cellulase-coding genes. This work, together with the previous investigations, suggests that all MAPKs are involved in cellulase formation, while Tmk3 is the only MAPK involved in signal transduction for the regulation of cellulase expression on the transcriptional level.

Contributing factors in the improvement of cellulosic H2 production in Clostridium thermocellum/Thermoanaerobacterium co-cultures.

Lignocellulosic biohydrogen is a promising renewable energy source that could be a potential alternative to the unsustainable fossil fuel-based energy. Biohydrogen production could be performed by Clostridium thermocellum that is the fastest known cellulose-degrading bacterium. Previous investigations have shown that the co-culture of C. thermocellum JN4 and a non-cellulolytic bacterium Thermoanaerobacterium thermosaccharolyticum GD17 produces more hydrogen than the C. thermocellum JN4 mono-culture, but the mechanism of this improvement is unknown. In this work, we carried out genomic and evolutionary analysis of hydrogenase-coding genes in C. thermocellum and T. thermosaccharolyticum, identifying one Ech-type [NiFe] hydrogenase complex in each species, and, respectively, five and four monomeric or multimeric [FeFe] hydrogenases in the two species. Further transcriptional analysis showed hydrogenase-coding genes in C. thermocellum are regulated by carbon sources, while hydrogenase-coding genes in T. thermosaccharolyticum are not. However, comparison between transcriptional abundance of hydrogenase-coding genes in mono- and co-cultures showed the co-culturing condition leads to transcriptional changes of hydrogenase-coding genes in T. thermosaccharolyticum but not C. thermocellum. Further metabolic analysis showed T. thermosaccharolyticum produces H2 at a rate 4-12-fold higher than C. thermocellum. These findings lead to the suggestion that the improvement of H2 production in the co-culture over mono-culture should be attributed to changes in T. thermosaccharolyticum but not C. thermocellum. Further suggestions can be made that C. thermocellum and T. thermosaccharolyticum perform highly specialized tasks in the co-culture, and optimization of the co-culture for more lignocellulosic biohydrogen production should be focused on the improvement of the non-cellulolytic bacterium.

A Tet-on and Cre-loxP Based Genetic Engineering System for Convenient Recycling of Selection Markers in Penicillium oxalicum.

The lack of selective markers has been a key problem preventing multistep genetic engineering in filamentous fungi, particularly for industrial species such as the lignocellulose degrading Penicillium oxalicum JUA10-1(formerly named as Penicillium decumbens). To resolve this problem, we constructed a genetic manipulation system taking advantage of two established genetic systems: the Cre-loxP system and Tet-on system in P. oxalicum JUA10-1. This system is efficient and convenient. The expression of Cre recombinase was activated by doxycycline since it was controlled by Tet-on system. Using this system, two genes, ligD and bglI, were sequentially disrupted by loxP flanked ptrA. The successful application of this procedure will provide a useful tool for genetic engineering in filamentous fungi. This system will also play an important role in improving the productivity of interesting products and minimizing by-product when fermented by filamentous fungi.

Regulation of cellulase expression, sporulation, and morphogenesis by velvet family proteins in Trichoderma reesei.

Homologs of the velvet protein family are encoded by the ve1, vel2, and vel3 genes in Trichoderma reesei. To test their regulatory functions, the velvet protein-coding genes were disrupted, generating Δve1, Δvel2, and Δvel3 strains. The phenotypic features of these strains were examined to identify their functions in morphogenesis, sporulation, and cellulase expression. The three velvet-deficient strains produced more hyphal branches, indicating that velvet family proteins participate in the morphogenesis in T. reesei. Deletion of ve1 and vel3 did not affect biomass accumulation, while deletion of vel2 led to a significantly hampered growth when cellulose was used as the sole carbon source in the medium. The deletion of either ve1 or vel2 led to the sharp decrease of sporulation as well as a global downregulation of cellulase-coding genes. In contrast, although the expression of cellulase-coding genes of the ∆vel3 strain was downregulated in the dark, their expression in light condition was unaffected. Sporulation was hampered in the ∆vel3 strain. These results suggest that Ve1 and Vel2 play major roles, whereas Vel3 plays a minor role in sporulation, morphogenesis, and cellulase expression.

Function of a p24 Heterodimer in Morphogenesis and Protein Transport in Penicillium oxalicum.

The lignocellulose degradation capacity of filamentous fungi has been widely studied because of their cellulase hypersecretion. The p24 proteins in eukaryotes serve important functions in this secretory pathway. However, little is known about the functions of the p24 proteins in filamentous fungi. In this study, four p24 proteins were identified in Penicillium oxalicum. Six p24 double-deletion strains were constructed, and further studies were carried out with the ΔerpΔpδ strain. The experimental results suggested that Erp and Pδ form a p24 heterodimer in vivo. This p24 heterodimer participates in important morphogenetic events, including sporulation, hyphal growth, and lateral branching. The results suggested that the p24 heterodimer mediates protein transport, particularly that of cellobiohydrolase. Analysis of the intracellular proteome revealed that the ΔerpΔpδ double mutant is under secretion stress due to attempts to remove proteins that are jammed in the endomembrane system. These results suggest that the p24 heterodimer participates in morphogenesis and protein transport. Compared with P. oxalicum Δerp, a greater number of cellular physiological pathways were impaired in ΔerpΔpδ. This finding may provide new insights into the secretory pathways of filamentous fungi.

[Current situation of scientific research capacity of schistosomiasis control institutions of municipal cities in Hubei Province].

OBJECTIVE: To evaluate the levels of the Chinese literature published by the schistosomiasis control institutions of 17 municipal cities of Hubei Province. METHODS: The related literature published from 2008 to 2012 was searched from the databases of CNKI, VIP and Wanfang and then screened by the exclusion criteria. NoteExpress and Excel softwares were applied to collect the literature and carry out the bibliometric analysis. RESULTS: A total of 168 papers were included and the schistosomiasis control institutes of Jingzhou City and Wuhan City had the highest amount. The literature was mainly published in Chinese Journal of Schistosomiasis Control and Journal of Public Health and Preventive Medicine. The comprehensive influence indexes of the schistosomiasis control institutes of Jingzhou, Wuhan and Qianjiang cities were higher. The schistosomiasis control institutes of Jingzhou City had an extensive content of literature while Wuhan was mainly focused on epidemiology, case report and Oncomelania hupensis snail control. CONCLUSION: The research of schistosomiasis in each municipal city has an extensive content and the research capacity of the schistosomiasis control institute of Jingzhou City is relatively outstanding.

Identification of the role of a MAP kinase Tmk2 in Hypocrea jecorina (Trichoderma reesei).

Despite the important role of MAPKs in signal transduction, their functions in the cellulase hyper-producing filamentous fungus Hypocrea jecorina haven't been studied except for the Hog1-like Tmk3. In this work, we constructed and explored the features of H. jecorina Δtmk2 to identify the role of this Slt2-homologous Tmk2. It is suggested from the results that Tmk2 is involved in cell wall integrity, sporulation and cellulase production. Although bearing similar roles in cell wall integrity maintenance, Tmk2 and Tmk3 appear to also have distinct functions: Tmk3 participates in high osmolarity resistance while Tmk2 does not; Tmk2 participates in sporulation but not Tmk3; Tmk3 is involved in promoting cellulase production while Tmk2 is involved in repressing cellulase formation. These studies provide the first insight into the function of Tmk2 in H. jecorina and contribute to understanding the signal transduction processes leading to the regulation of cellulase production in this important cellulase hyper-producer.

[Performance of detection and treatment in schistosomiasis in Hubei Province, 2011].

OBJECTIVE: To evaluate the performance of schistosomiasis detection and treatment program in Hubei Province in 2011, so as to enhance the benefit and management of the program. METHODS: In 63 schistosomiasis epidemic counties of Hubei Province, there were 3 types of endemic situation, that was endemic controlled, transmission controlled, and transmission interrupted. Six counties (districts) in each type were selected by the stratified random sampling method. The data including schistosomiasis detection and treatment, fund utilization and others were collected and analyzed statistically in 2011. RESULTS: The completion rate of schistosomiasis detection task was 103.9% and the completion rate of chemotherapy task 106.9%. The total fund was 73.815 million Yuan. The detection cost accounted for 12.0% while the chemotherapy cost accounted for 4.9%. The detection cost per capita was 9.03 Yuan and the treatment cost per capita was 10.35 Yuan. The cost effectiveness ratio was 1:6.1 and the net cost effectiveness ratio was 1:5.1. CONCLUSION: The social-economic benefits in schistosomiasis control and treatment are obvious. However, the resource allocation still needs to be optimized.

[Bibliometric research on Chinese literatures published by five provincial institutes of schistosomiasis prevention and control in lake regions of China from 2002 to 2011].

OBJECTIVE: To evaluate the status of the Chinese literatures published by the 5 institutes of schistosomiasis prevention and control in Hunan, Hubei, Jiangxi, Anhui, and Jiangsu provinces from 2002 to 2011. METHODS: All the Chinese literatures on schistosomiasis research published by the five provincial institutes of schistosomiasis prevention and control in lake regions of China from 2002 to 2011 were collected and analyzed by using the bibliometric software NoteExpress 2. Authors, journals, published date, and study affiliations were captured. RESULTS: The number of the published literatures from 2002 to 2011 was 1 127 and the comprehensive influence index was 984.547 presenting an uptrend. Most of the papers were published in the Chinese Journal of Schistosomiasis Control accounting for 50.5%, and the core authors based on Zhou, Liang, and Hong were formed. Jiangsu Institute of Parasitic Diseases was the first in all the statistical indexes. However, there existed an unbalanced phenomenon among the five provinces in the total status, author's information and the comprehensive influence index. CONCLUSIONS: The number of the literatures increased steadily and the quality improved especially in Jiangsu Province. However, there exists an obvious imbalance in literature type distribution. The communication of scientific research is an urgent need in order to improve scientific research.

A mitogen-activated protein kinase Tmk3 participates in high osmolarity resistance, cell wall integrity maintenance and cellulase production regulation in Trichoderma reesei.

The mitogen-activated protein kinase (MAPK) pathways are important signal transduction pathways conserved in essentially all eukaryotes, but haven't been subjected to functional studies in the most important cellulase-producing filamentous fungus Trichoderma reesei. Previous reports suggested the presence of three MAPKs in T. reesei: Tmk1, Tmk2, and Tmk3. By exploring the phenotypic features of T. reesei Δtmk3, we first showed elevated NaCl sensitivity and repressed transcription of genes involved in glycerol/trehalose biosynthesis under higher osmolarity, suggesting Tmk3 participates in high osmolarity resistance via derepression of genes involved in osmotic stabilizer biosynthesis. We also showed significant downregulation of genes encoding chitin synthases and a ß-1,3-glucan synthase, decreased chitin content, 'budded' hyphal appearance typical to cell wall defective strains, and increased sensitivity to calcofluor white/Congo red in the tmk3 deficient strain, suggesting Tmk3 is involved in cell wall integrity maintenance in T. reesei. We further observed the decrease of cellulase transcription and production in T. reesei Δtmk3 during submerged cultivation, as well as the presence of MAPK phosphorylation sites on known transcription factors involved in cellulase regulation, suggesting Tmk3 is also involved in the regulation of cellulase production. Finally, the expression of cell wall integrity related genes, the expression of cellulase coding genes, cellulase production and biomass accumulation were compared between T. reesei Δtmk3 grown in solid state media and submerged media, showing a strong restoration effect in solid state media from defects resulted from tmk3 deletion. These results showed novel physiological processes that fungal Hog1-type MAPKs are involved in, and present the first experimental investigation of MAPK signaling pathways in T. reesei. Our observations on the restoration effect during solid state cultivation suggest that T. reesei is evolved to favor solid state growth, bringing up the proposal that the submerged condition normally used during investigations on fungal physiology might be misleading.

Factors involved in the response to change of agitation rate during cellulase production from Penicillium decumbens JUA10-1.

Improvement of agitation is a commonly used approach for the optimization of fermentation processes. In this report, the response to improving agitation rate from 150 to 250 rpm on cellulase production from Penicillium decumbens JUA10-1 was investigated. It was shown that the production of all the major components of the cellulase mixture increased following improved agitation. Further investigations showed that at least three factors are involved in this improvement: the improved biomass accumulation, proportion of active/mature cellulases, and cellulase transcription level. The transcription levels of the cellulase repressing transcription factor ace1 and the cellulase activating transcription factor xlnR, however, both declined when a higher agitation was applied. These observations, along with our analysis of the carbon catabolite repressor CreA, lead to the suggestion that the molecular mechanism underlying improved cellulase transcription is the competition of two concurrent effects following improved agitation: CreA-mediated derepression induced by the downregulation of ace1, and CreA-mediated deactivation induced by the downregulation of xlnR.