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Programmed autolytic bacteria, also termed controlled self-disruptive or self-destructive bacteria, are bacterial systems that express certain lytic genes and undergo cell lysis at a predetermined time point to release the intracellular contents or to commit suicide. Such systems have wide applications in high-throughput screening of protein libraries, synthesis and recovery of bio-products, population control of heterogeneous cultures or synthetic co-cultures, drug delivery, and food fermentation. Recently, great achievements have been reported regarding on-demand control of cell autolysis for different purposes, highlighting the potential of autolytic strains in biomanufacturing and biomedicine. In this review article, we first introduce the various applications of such bacteria, followed by a summarization of the approaches used in the establishment of autolytic bacterial systems, including cell autolysis mediated by cell wall hydrolases with or without facilitating proteins and by membrane-disturbing proteins. Next, we describe in detail the methodologies adopted to control and initiate cell lysis, including induction by chemical inducers, stimulation by physical signals, auto-induction by metabolic status or nutrient limitation, and constitutive expression of the lytic genes. This article is ended with discussions on the remaining problems and possible future directions. This review provides comprehensive information on autolytic bacteria and insightful guidance to the development of highly efficient, robust, and smart autolytic bacterial platforms. [ABSTRACT FROM AUTHOR]

Crop production has become a priority issue in recent years because of the exponential growth of the world's population and the need to find substitutes for chemical fertilizers. The latter is under the spotlight in order to achieve a more sustainable approach in a cost-effective way. Biostimulants have gained attention as an alternative to chemical fertilizers. Although they are not considered fertilizers as inputs of nutrients, they stimulate plants' nutrition and tolerance to stress, among other characteristics. In the literature, amino acid-based biostimulants have been found to be effective. This review focuses on the effectiveness of biostimulants, their presence in the global market, and their production with fish by-products as a source, using enzymatic hydrolysis and autolysis, with a particular focus on fish viscera, their possibilities in the agricultural sector, and their availability in Europe for possible opportunities. Fish viscera protein hydrolysates for biostimulant production seem a feasible alternative to fishmeal production in Europe, especially in areas located far from fishmeal plants. [ABSTRACT FROM AUTHOR]

Wine lees, the residue left behind after racking or bottling of wine, are predominantly composed of dead yeast cells, ethanol, phenolic compounds, and tartrates. Yeast extract (i.e., commercial yeast extract), a highly nutritious powder derived from commercially cultivated yeast biomass, is commonly used in nutrient media as a nitrogen source. In the context of by-product valorization, wine lees could potentially be used to produce a substitute for commercial yeast extract (CYE). In our study we investigated the growth and fermentative ability of two major winemaking microorganisms, Lactiplantibacillus plantarum and Saccharomyces cerevisiae, in culture media containing a wine lees yeast extract (WLYE) and a CYE. The effects of yeast extract type, concentration, and initial cell concentration (y0) on key kinetic parameters—maximum specific growth rate (μmax), lag phase duration (λ), and maximum cell concentration (ymax)—were evaluated. For L. plantarum, the results showed that using a WLYE led to similar kinetic parameters to those obtained with a CYE, with λ being unaffected by y0 in samples containing a WLYE. For S. cerevisiae, simultaneous addition of both yeast extracts led to increased μmax values (up to 0.136 h−1) compared to individually added yeast extracts, although this negatively affected λ and ymax. Current research on wine lees is mainly focused on using them as a substrate to produce valuable metabolites through fermentation, overlooking the potential industrial applications of the nutrient-rich autolysate. The findings of this study appear promising for the holistic valorization of wine lees, contributing towards the concepts of sustainability and circular economy. [ABSTRACT FROM AUTHOR]

Biosorption is a good choice for removal of pollutants from water. In this study, hull cell of thermally autolyzed baker yeast, was used as a low-cost biosorbent against U(VI) pollution. The changes of biomass properties due to autolysis were analyzed using SEM, FTIR and BET techniques. Uranium (VI) biosorption capacity was evaluated and the effective parameters were examined by Placket Burman Design and the levels of significant factors (including pH, biomass concentration, initial U(VI) concentration) were further optimized using Response Surface Methodology. Based on the results obtained from the proposed quadratic model, maximum U uptake (84 mg/g) was occurred under optimum conditions including: 2.0 g biomass/L, pH value of 4.5 and 300 mg/L of initial U(VI) concentration. Furthermore, the experimental data were fitted to pseudo-first-order kinetic model (R2 = 0.991) and Freundlich isotherm model (R2 = 0.965). Uranium is desorbed in the presence of diluted solutions of sulfuric acid (about 70%) indicated the potential of the metal recovery. [ABSTRACT FROM AUTHOR]

Abstract This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts’ biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance.

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The morphometric characteristics of brain tissue were studied based on autopsy material from 49 deceased newborns divided into 7 groups based on the time after death. Samples were taken from the upper (frontal lobe) and lower (occipital lobe) regions relative to the supine position of the body. Paraffin sections were prepared from these samples and stained with hematoxylin and eosin. Histological preparations were analyzed using an image analysis system to determine the area of gliocyte nuclei, cross-cut blood vessels, and expanded area around them in the white matter of the brain. Based on these data, severity indices were calculated for both cellular (pericellular) and vascular (perivascular) expansion. The dynamics of changes in morphometric parameters within the range of cellular and vascular alterations on brain tissue specimens, which reflect the development of postmortem hypostasis and autolysis in this organ, can be used to estimate the duration of the postmortem interval. At the same time, these changes, when combined with other non-specific postmortem findings, should be distinguished from long-term pathological processes and diseases that may have occurred during life. [ABSTRACT FROM AUTHOR]

Quantifying the formation and decomposition of amyloid is a crucial issue in the development of new drugs and therapies for treating amyloidosis. The current technologies for grasping amyloid formation and decomposition include fluorescence analysis using thioflavin-T, secondary structure analysis using circular dichroism, and image analysis using atomic force microscopy or transmission electron microscopy. These technologies typically require spectroscopic devices or expensive nanoscale imaging equipment and involve lengthy analysis, which limits the rapid screening of amyloid-degrading drugs. In this study, we introduce a technology for rapidly assessing amyloid decomposition using capillary flow-based paper (CFP). Amyloid solutions exhibit gel-like physical properties due to insoluble denatured polymers, resulting in a shorter flow distance on CFP compared to pure water. Experimental conditions were established to consistently control the flow distance based on a hen-egg-white lysozyme amyloid solution. It was confirmed that as amyloid is decomposed by trypsin, the flow distance increases on the CFP. Our method is highly useful for detecting changes in the gel properties of amyloid solutions within a minute, and we anticipate its use in the rapid, large-scale screening of anti-amyloid agents in the future. [ABSTRACT FROM AUTHOR]

This study investigated the antibacterial properties of Coptis rhizome, a plant traditionally used for respiratory infections, against Streptoccus pneumonia (S. pneumoniae), for which there has been minimal empirical evidence of effectiveness. The study particularly examined autolysis, indirectly associated with antibacterial resistance, when using Coptis rhizome for bacterial infections. In our methodology, Coptis rhizome was processed with ethanol and distilled water to produce four different extracts: CRET30, CRET50, CRET70, and CRDW. The antibacterial activity of these extracts were tested through Minimum Inhibitory Concentration (MIC) assays, disk diffusion tests, and time-kill assays, targeting both standard (ATCC 49619) and resistant (ATCC 70067) strains. The study also evaluated the extracts' biofilm inhibition properties and monitored the expression of the lyt gene, integral to autolysis. The results prominently showed that the CRET70 extract demonstrated remarkable antibacterial strength. It achieved an MIC of 0.125 µg/mL against both tested S. pneumoniae strains. The disk diffusion assay recorded inhibition zones of 22.17 mm for ATCC 49619 and 17.20 mm for ATCC 70067. Impressively, CRET70 resulted in a 2-log decrease in bacterial numbers for both strains, showcasing its potent bactericidal capacity. The extract was also effective in inhibiting 77.40% of biofilm formation. Additionally, the significant overexpression of the lytA gene in the presence of CRET70 pointed to a potential mechanism of action for its antibacterial effects. The outcomes provided new perspectives on the use of Coptis rhizome in combating S. pneumoniae, especially significant in an era of escalating antibiotic resistance. [ABSTRACT FROM AUTHOR]

Brain death is a not uncommon phenomena in the adult and pediatric population. Most cases are removed from life support soon after brain death is declared. Less commonly, systemic perfusion is maintained by life support for some time after neurologic function stops. These cases present uncommon opportunities to explore the histology of necrosis and autolysis in the context of global hypoxic ischemic damage. Here, we describe the unusual case of an infant maintained on life support for 2 weeks after brain death was declared with an emphasis on the resulting gross and histologic findings including a discussion of their underlying physiology. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis is a green approach for nutrient bioconversion of sea cucumber body wall to recover sulfated polysaccharides. However, formation of high level of advanced glycation end products (AGEs) can potentially negate health benefits of the functional food. In this study, UV-assisted autolysis was employed to optimize nutrient bioconversion of Stichopus horrens body wall using extreme UV dosage (324,000-648,000 J/m2), different autolysis temperatures (40–60 °C) and time (3–5 h). Parallel biochemical changes indicate that UV irradiation promoted the activation of endogenous enzymes, leading to the proteolysis of the body wall and the subsequent dissolution of sulfated polysaccharides. Changes in the amide band I region of the Fourier-transform infrared (FTIR) spectra of autolyzed body wall residue reflected the loss of α-helix secondary structures of collagen which exacerbated at autolysis temperatures beyond 50 °C. The maximum yield of sulfated polysaccharides and antioxidant activities were obtained at the condition (486,000 J/m2 of UV dosage, 60 ℃, and 4 h of autolysis) by the optimization using the central composite design. The nutritional composition and safety aspect of the autolysate was compared with hydrolysate from enzymatic hydrolysis and hot water extract. Quantification of 5-hydroxymethylfurfural (HMF) showed that UV-assisted autolysis could mitigate HMF formation (0.12 mg/kg) by 97.6% compared to enzymatic hydrolysis (5.13 mg/kg) and 42.9% compared to hot water extraction (0.21 mg/kg). The UV-assisted autolysis with metal ion further enhanced the extraction process of sulfated polysaccharides from sea cucumber body wall and reduction of the processing contaminants. Thus, UV-assisted autolysis offers a safer alternative for the nutrient bioconversion of sea cucumber body wall, particularly for the development of functional foods. [ABSTRACT FROM AUTHOR]

Death initiates a cascade of physiological and biochemical alterations in organs and tissues, resulting in microscopic changes that challenge the histopathological evaluation. Moreover, the brain is particularly susceptible to artifacts owing to its unique composition and its location within the cranial vault. The aim of this study was to compile and illustrate the microscopic changes in the central nervous system (CNS) of rats subjected to delayed postmortem fixation. It also scrutinizes the influence of exsanguination and cooling methods on the initiation and progression of these alterations. Twenty-four Wistar Han outbred rats (RccHanTM: WIST) were sacrificed and stored either at room temperature (18-22°C) or under refrigeration (2-4°C). Necropsies were conducted at different time points postmortem (i.e., 0.5  h, 1  h, 4  h, 8  h, 12  h, 24  h, 36  h, 48  h, 7  days and 14  days). Brain sections underwent simultaneous digital evaluation by 14 pathologists until a consensus was reached on terminology, key findings, and intensity levels. Microscopic observations varied among cell types. Glial cells were similarly affected throughout the CNS and showed pericellular halo, chromatin condensation and nuclear shrinkage. Neurons showed two types of postmortem changes as most of them showed progressive shrinkage, cytoplasmic dissolution and karyorrhexis whereas others acquired a dark-neuron-like appearance. Neuronal changes showed marked differences among neuroanatomical locations. Additional postmortem changes encompassed: granulation and microcavitation in neuropil and white matter; retraction spaces; detachment of ependyma, choroid plexus, and leptomeninges. Severity of findings after 48  h at room temperature was higher than after seven days under refrigeration and similar to or slightly lower than after 14  days under refrigeration. No clear differences were observed related to the sex or weight of the animals or their exsanguination status. This work elucidates the onset and progression of autolytic changes in the brains of Wistar Han rats, offering insights to accurately identify and enhance the histopathological evaluation. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the sequential hydrolysis of the biomass from unconventional and versatile Y. lipolytica to recover mannoproteins, carbohydrates, and other compounds as well as to determine the antioxidant activity of ultrafiltered fractions. The crude biomass underwent autolysis, and the resulting supernatant fraction was used for mannoprotein recovery via precipitation with ethanol. The precipitate obtained after autolysis underwent acid hydrolysis, and the resulting supernatant was ultrafiltered, precipitated, and characterized. The process yields were 55.5% and 46.14% for the crude biomass grown in glucose and glycerol, respectively. The mannoprotein with higher carbohydrate content (from crude biomass grown in glycerol) exhibited a higher emulsification index of 47.35% and thermal stability (60% weight loss). In contrast, the mannoprotein with higher protein content (from crude biomass grown in glucose) showed a better surface tension reduction of 44.50 mN/m. The technological properties showed that the crude biomass and the food ingredients are feasible to apply in food processing. The fractionation of the acid hydrolysis portion allowed the evaluation of the antioxidant power synergism among the components present in the hydrolysate, mostly the protein peptide chain. The sequential hydrolysis method is viable for extracting valuable products from Y. lipolytica. [ABSTRACT FROM AUTHOR]

Yang Yang,1,2 Zongze Yao,1 Jiazhen Zhang,1 Wei Shao,3 Bo Li,2 Huihui Wu,2 Wenjian Tang,3 Jing Zhang2 1School of Medicine, Anhui University of Science and Technology, Huainan, People’s Republic of China; 2Anhui Province Key Laboratory of Occupational Health, Anhui No.2 Provincial People’s Hospital, Hefei, People’s Republic of China; 3School of Pharmacy, Anhui Medical University, Hefei, People’s Republic of ChinaCorrespondence: Wenjian Tang; Jing Zhang, Tel +86-551-63672601, Email ahmupharm@126.com; hfzj2552@163.comBackground: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of staph infection that is difficult to treat because of resistance to some antibiotics. A recent study indicated that diarylurea ZJ-2 is a novel antibacterial agent against multi-drug resistant Enterococcus faecium. In this work, we refined the bactericidal mechanism of ZJ-2 as a peptidoglycan (PG) hydrolase by affecting AtlA-mediated PG homeostasis.Methods: A wild-type strain (WT) and a mutant strain (ΔatlA) were used to investigate the effects of ZJ-2 on the cell wall, PG, and autolysin regulatory system by antimicrobial susceptibility testing, hemolytic toxin assay, microanalysis, autolysis assay, qRT-PCR, ELISA and mouse model of pneumonia.Results: The results revealed that ZJ-2 down-regulated the expression of genes related to peptidoglycan hydrolase (PGH) (sprX, walR, atlA, and lytM), and reduced the levels of PG, muramyl dipeptide (MDP), cytokines, and hemolytic toxin, while ΔatlA interfered with the genes regulation and PG homeostasis. In the mouse MRSA pneumonia model, the same trend was observed in the nucleotide oligomerization domain protein 2 (NOD2) and relative proinflammatory factors.Conclusion: ZJ-2 may act as a novel inhibitor of PG hydrolyse, disrupting autolysin-mediated PG homeostasis, and reducing inflammation by down-regulating the MDP-NOD2 pathway. Keywords: MRSA, peptidoglycan hydrolase, homeostasis, autolysis, NOD2

Abstract Background Autolysis by cellular peptidoglycan hydrolases (PGH) is a well-known phenomenon in bacteria. During food fermentation, autolysis of starter cultures can exert an accelerating effect, as described in many studies on cheese ripening. In contrast, very little is known about autolysis of starter cultures used in other fermentations. Staphylococcus (S.) carnosus is often used in raw sausage fermentations, contributing to nitrate reduction and flavor formation. In this study, we analyzed the influence of PGHs of the strains S. carnosus TMW 2.146 and S. carnosus TMW 2.2525 on their autolytic behavior. The staphylococcal major autolysin (Atl), a bifunctional enzyme with an N-acetylmuramoyl-L-alanine amidase and a glucosaminidase as an active site, is assumed to be the enzyme by which autolysis is mainly mediated. Results AtlC mutant strains showed impaired growth and almost no autolysis compared to their respective wild-type strains. Light microscopy and scanning electron microscopy showed that the mutants could no longer appropriately separate from each other during cell division, resulting in the formation of cell clusters. The surface of the mutants appeared rough with an irregular morphology compared to the smooth cell surfaces of the wild-types. Moreover, zymograms showed that eight lytic bands of S. carnosus, with a molecular mass between 140 and 35 kDa, are processed intermediates of AtlC. It was noticed that additional bands were found that had not been described in detail before and that the banding pattern changes over time. Some bands disappear entirely, while others become stronger or are newly formed. This suggests that AtlC is degraded into smaller fragments over time. A second knockout was generated for the gene encoding a N-acetylmuramoyl-L-alanine amidase domain-containing protein. Still, no phenotypic differences could be detected in this mutant compared to the wild-type, implying that the autolytic activity of S. carnosus is mediated by AtlC. Conclusions In this study, two knockout mutants of S. carnosus were generated. The atlC mutant showed a significantly altered phenotype compared to the wild-type, revealing AtlC as a key factor in staphylococcal autolysis. Furthermore, we show that Atl is degraded into smaller fragments, which are still cell wall lytic active.

This study demonstrated a deproteinization of white shrimp waste using the autolysis method. The deproteinization process was initially carried out using an acidic water solution (pH ∼ 2.5) for 3 or 5 d. The obtained filtrate was then used to incubate another fresh shrimp waste for several cycles using parameters similar to the initial stage. A significant increase in filtrate protein content was observed, which agreed with the UV–Vis spectroscopy results. UV–Vis spectra revealed the considerable effect of filtrate usage on the rise of tryptophan content in the hydrolysate, which was indicated by the increase of peak area at around 290 nm. The highest protein content was 12.49 ± 0.0004 % obtained in filtrate day 15 (FD15). On the other hand, the total nitrogen content of the obtained residue decreased. Infrared spectra confirmed the disappearance of several functional groups (N–H and CO) from the residue. This can be indicated by the significant decrease of the A1621/A1111 value, representing the loss of CO peptide groups in the protein. FTIR spectra of the obtained residue showed mainly the structure of chitin, and it became cleaner when filtrate was used as an incubator solution. The method applies the concept of sustainability and plays a vital role in reducing water use and preserving groundwater.

ABSTRACTStreptococcus mutans (S. mutans) is one of the major etiological agents of dental caries. Interfering with the expression of genes associated with cariogenicity of S. mutans is an effective ecological approach for caries prevention. Thus, understanding the role of genes related to cariogenicity in S. mutans is important. dltD is a conserved gene in Gram-positive bacteria, which is involved in D-alanylation of lipoteichoic acid to modify cell surface charge. In vivo caries experiments have shown significant decreases in the caries severity in rats infected with S. mutans dltD-deficient strain. Although the impact of dltD on bacterial surface charge and division in other Gram-positive bacteria is known, its role in S. mutans biological functions remains unclear. This study aimed to investigate the biological functions of dltD in S. mutans. We examined growth curves, morphology, autolysis, biofilm formation, and cell membrane properties of S. mutans wild strain and dltD-deficient strain. Our results revealed that dltD plays a key role in the growth and autolysis of S. mutans. dltD deletion increased biofilm autolysis, thereby reducing the number of viable bacteria within the biofilm. Furthermore, dltD may have an epistatic effect on cell division and surface charge. Its regulatory network needs to be further elucidated. This study shed light on therole of dltD in the growth of S. mutans, thereby enhancing our understanding of its function.

Sea cucumbers were stored live in 25% oxygen or 25 mg/mL of ascorbic acid for 7 days, for comparison purposes. The condition of the individuals was assessed through the sensory scores, bacterial communities, and biochemical indexes. The oxygen treatment extended preservation by 2 days compared to ascorbic acid. After 7 days, the total volatile basic nitrogen and the microbial content in all sea cucumbers were within acceptable limits. The actin degradation rate reached 1.3416 ± 0.03%, and cathepsin B and L increased by 94.6% and 59.1%, respectively, in the Control group. The quality decline of sea cucumbers during storage was caused by autolysis rather than spoilage organisms. (1) The evidence indicates autolysis occurred during sea cucumber storage, with 94.6% and 59.1% improvement in cathepsin B and L, respectively, and actin degradation of 1.3416 ± 0.03%. (2) The quality decline of sea cucumbers during storage was caused by autolysis rather than spoilage organisms. (3) The score evaluation revealed that the preservation time was two days longer with oxygen treatment (25%) than with ascorbic acid treatment (25 mg/mL). [ABSTRACT FROM AUTHOR]

We studied morphometric changes in the liver acini of dead newborns depending on the duration of the postmortem period. Autopsy samples of the liver tissue from 49 dead newborns were divided into 7 groups depending on the time of death. Liver tissue samples were taken from the upper and lower areas of the liver in the supine position of newborns; paraffin sections were prepared and stained with hematoxylin and eosin. The morphometric analysis of histological preparations revealed a progressive decrease in the mean size of the liver plates (trabeculae) and, conversely, an increase in the area of sinusoids with increasing the duration of the postmortem period; these changes were due to the postmortem redistribution of the blood and autolysis processes. More significant changes were noted in acinar zone 3 of the lower part of the liver. The revealed intra-acinar features of postmortem changes should be taken into account for their differential diagnosis with pathological processes that developed during life, in particular, the signs of congestion and peliosis of the liver. [ABSTRACT FROM AUTHOR]

Importance: In veterinary forensic science, accurately determining the postmortem interval (PMI) is crucial for identifying the causes of animal deaths. Autolysis, a significant postmortem process, influences PMI estimation, but its relationship with humidity is not well understood. Objective: This study aimed to improve the accuracy of PMI estimates in veterinary forensic cases by looking into how different humidity levels affect autolysis in different organs of rats. Methods: The study involved 38 male rats, examining histopathological changes in their heart, liver, and pancreas. These organs were subjected to controlled humidity levels (20%, 55%, and 80%) at a constant 22°C. Tissue samples were collected at several intervals (0 h, 12 h, 24 h, 3 days, and 8 days) for comprehensive analysis. Results: Distinct autolytic characteristics in animal organs emerged under varying humidity conditions. The low-humidity environment rapidly activated autolysis more than the high-humidity environment. In addition, it was found that lower humidity caused nuclear pyknosis, cytoplasmic disintegration, and myofiber interruption. The liver, in particular, showed portal triad aggregation and hepatocyte individuation. The pancreas experienced cell fragmentation and an enlarged intracellular space. High humidity also caused the loss of striations in cardiac tissues, and the liver showed vacuolation. Under these conditions, the pancreas changed eosinophilic secretory granules. Conclusions and Relevance: The study successfully established a clear connection between the autolytic process in PMIs and relative humidity. These findings are significant for developing a more accurate and predictable method for PMI estimation in the field of veterinary forensic science. [ABSTRACT FROM AUTHOR]

TsaB/YeaZ represents a promising target for novel antibacterial agents due to its indispensable role in bacterial survival, high conservation within bacterial species, and absence of eukaryotic homologs. Previous studies have elucidated the role of the essential staphylococcal protein, TsaB/YeaZ, in binding DNA to mediate the transcription of the ilv-leu operon, responsible for encoding key enzymes involved in the biosynthesis of branched-chain amino acids—namely isoleucine, leucine, and valine (ILV). However, the regulation of ILV biosynthesis does not account for the essentiality of TsaB/YeaZ for bacterial growth. In this study, we investigated the impact of TsaB/YeaZ depletion on bacterial morphology and gene expression profiles using electron microscopy and deep transcriptomic analysis, respectively. Our results revealed significant alterations in bacterial size and surface smoothness upon TsaB/YeaZ depletion. Furthermore, we pinpointed specific genes and enriched biological pathways significantly affected by TsaB/YeaZ during the early and middle exponential phases and early stationary phases of growth. Crucially, our research uncovered a regulatory role for TsaB/YeaZ in bacterial autolysis. These discoveries offer fresh insights into the multifaceted biological functions of TsaB/YeaZ within S. aureus. [ABSTRACT FROM AUTHOR]

Introduction: Pholiota nameko is a widely consumed edible fungus. This study focuses on two crucial developmental stages of Pholiota nameko, namely, mycelium and ascospores. The objectives of this research were to investigate changes in microbial diversity and community structure during the growth of Pholiota nameko and to analyze the adaptability of the dominant strains to their respective habitats through metabolic. Methods: Specifically, we conducted second-generation sequencing of the 16S rRNA gene (Illumina) on samples obtained from these stages. In addition, we isolated and characterized endophytes present in Pholiota nameko, focusing on examining the impact of dominant endophyte genera on autolysis. We also conducted a metabolic pathway analysis. Results and discussion: The results unveiled 578,414 valid sequences of Pholiota nameko endophytic fungi. At the phylum level, the dominant taxa were Basidiomycota, Ascomycota, Zoopagomycota, and Mucoromycota. At the genus level, the dominant taxa observed were Pholiota, Inocybe, Fusarium, and Hortiboletus. For endophytic bacteria, we obtained 458,475 valid sequences. The dominant phyla were Proteobacteria, TM6, Firmicutes, and Bacteroidetes, while the dominant genera were Edaphobacter, Xanthomonas, Burkholderia, and Pseudomonas. Moreover, we identified the isolated strains in Pholiota nameko using 16S rDNA, and most of them were found to belong to the genus Pseudomonas, with Pseudomonas putida being the most prevalent strain. The findings revealed that the Pseudomonas putida strain has the ability to slow down the breakdown of soluble proteins and partially suppress the metabolic processes that generate superoxide anion radicals in Pholiota nameko, thereby reducing autolysis. Additionally, our results demonstrated that molybdenum enzyme-mediated anaerobic oxidative phosphorylation reactions were the primary energy metabolism pathway in the Pseudomonas putida strain. This suggests that the molybdenum cofactor synthesis pathway might be the main mechanism through which Pholiota nameko adapts to its complex and diverse habitats. [ABSTRACT FROM AUTHOR]

Background: Autolysis by cellular peptidoglycan hydrolases (PGH) is a well-known phenomenon in bacteria. During food fermentation, autolysis of starter cultures can exert an accelerating effect, as described in many studies on cheese ripening. In contrast, very little is known about autolysis of starter cultures used in other fermentations. Staphylococcus (S.) carnosus is often used in raw sausage fermentations, contributing to nitrate reduction and flavor formation. In this study, we analyzed the influence of PGHs of the strains S. carnosus TMW 2.146 and S. carnosus TMW 2.2525 on their autolytic behavior. The staphylococcal major autolysin (Atl), a bifunctional enzyme with an N-acetylmuramoyl-L-alanine amidase and a glucosaminidase as an active site, is assumed to be the enzyme by which autolysis is mainly mediated. Results: AtlC mutant strains showed impaired growth and almost no autolysis compared to their respective wild-type strains. Light microscopy and scanning electron microscopy showed that the mutants could no longer appropriately separate from each other during cell division, resulting in the formation of cell clusters. The surface of the mutants appeared rough with an irregular morphology compared to the smooth cell surfaces of the wild-types. Moreover, zymograms showed that eight lytic bands of S. carnosus, with a molecular mass between 140 and 35 kDa, are processed intermediates of AtlC. It was noticed that additional bands were found that had not been described in detail before and that the banding pattern changes over time. Some bands disappear entirely, while others become stronger or are newly formed. This suggests that AtlC is degraded into smaller fragments over time. A second knockout was generated for the gene encoding a N-acetylmuramoyl-L-alanine amidase domain-containing protein. Still, no phenotypic differences could be detected in this mutant compared to the wild-type, implying that the autolytic activity of S. carnosus is mediated by AtlC. Conclusions: In this study, two knockout mutants of S. carnosus were generated. The atlC mutant showed a significantly altered phenotype compared to the wild-type, revealing AtlC as a key factor in staphylococcal autolysis. Furthermore, we show that Atl is degraded into smaller fragments, which are still cell wall lytic active. [ABSTRACT FROM AUTHOR]

CNS tumor diagnosis in dogs often relies on immunohistochemistry (IHC) given similar histologic features among tumors. Most CNS tissue samples encountered by diagnostic pathologists are collected during autopsy, and postmortem specimens can be susceptible to autolysis and prolonged formalin fixation, both of which have the potential to influence IHC results and interpretation. Here we evaluated the effects of experimentally controlled autolysis induced by delayed tissue fixation (sections of brain held for 2, 4, 8, 12, 24, 48, and 72 h in 0.9% NaCl at either room temperature or 37°C prior to fixation) as well as the effects of prolonged formalin fixation times (1 wk, 1 mo, 2 mo) on a panel of 8 IHC markers (CNPase, GFAP, Iba1, OLIG2, PGP9.5, MAP2, NeuN, synaptophysin) relevant to brain tumor diagnosis. Prolonged fixation of up to 2 mo had no detrimental effect on any immunomarker except NeuN, which had reduced immunolabeling intensity. Delayed fixation led to autolytic changes as expected, on a gradient of severity corresponding to increased time in saline prior to fixation. Several immunomarkers should be used with caution (CNPase, OLIG2) or avoided entirely (MAP2, NeuN) in markedly autolyzed brain and brain tumor tissues. Our results suggest that autolysis has minimal effect on most immunomarkers, but that advanced autolysis may cause a loss of specificity for GFAP, MAP2, and PGP9.5, a loss of intensity of CNPase and OLIG2, and loss of labeling with MAP2 and NeuN. Prolonged fixation affected only NeuN, with mildly decreased intensity. [ABSTRACT FROM AUTHOR]

Beer stability, influenced by physical, chemical, and biological factors, poses a considerable challenge for breweries. Biological stability, as a major concern, is effectively managed through practices such as good hygiene, pasteurization, and filtration. Microbiological contamination, often recognizable by increased turbidity or off-flavours, is influenced by temperature, with optimal conditions promoting the growth of specific microorganisms. Lower temperatures slow down flavour changes and chemical reactions in beer, impacting its non-biological stability. This case study explores the impact of storage temperature on autolysis off-flavour development in 10 different unfiltered and unpasteurized beers. The results showed that autolysis off-flavour occurred at both low and higher storage temperatures and that its dependence on the temperature was minimal. This unexpected fact was discovered mainly due to uncovered significant contamination of the commercial beers tested (wild yeasts, lactic acid bacteria, enterococci and coliform bacteria). For this reason, the concentration of cells in the beer appeared as a more influential factor in the development of off-flavours, including autolysis, than the storage temperature. The partial results need to be studied in more detail, nevertheless, we felt it was important to publish the revelation of a strong contamination of beers purchased from regular stores for our experiments. At this point it can already be concluded that the low storage temperature did not help to prevent the development of the contamination and the associated sensory deterioration of the beers. [ABSTRACT FROM AUTHOR]

Acute pancreatitis is caused by trypsinogen activation in acinar cells caused by various injury forms (gallstone, high triglycerides, alcohol, etc.). Viral pancreatitis is a clinically rare disease type, which is easily neglected by clinicians and causes serious adverse consequences. Viral pancreatitis involves the entry of viruses into pancreatic cells, triggering inflammation, immune response activation, and enzymatic autodigestion, leading to tissue damage and potential complications. At present, there are few available reports on viral pancreatitis, most of which are case reports. This review brings attention to clinicians by describing the incidence of viral pancreatitis to enhance clinical understanding and patient care. [ABSTRACT FROM AUTHOR]

Summary: Rapid softening of texture is a major problem associated with quality loss and consumer rejection of harpiosquillid mantis shrimp (Harpiosquilla raphidea) (HMS). Effects of endogenous proteases in muscles and digestive tract on protein degradation and softening were investigated. Scanning electron microscopic and histological images indicated drastic destruction of muscle during iced storage. Based on autolysis, maximal activity was found at pH 8.5 and 55 °C, and serine proteases including trypsin were dominant. Cathepsin B and L + B in muscle were altered throughout storage, while trypsin remained constant in HMS meat for 1–3 days. Firmness and toughness decreased and coincided with augmented degradation of myofibrillar proteins and collagen. Trypsin from the digestive tract was contaminated into the abdomen during iced storage, therefore inducing drastic hydrolysis of muscle proteins. This phenomenon caused the undesirable pasty/mushy texture associated with the loss in firmness and toughness of meat within 3 days of storage. [ABSTRACT FROM AUTHOR]

Death initiates a cascade of physiological and biochemical alterations in organs and tissues, resulting in microscopic changes that challenge the histopathological evaluation. Moreover, the brain is particularly susceptible to artifacts owing to its unique composition and its location within the cranial vault. The aim of this study was to compile and illustrate the microscopic changes in the central nervous system (CNS) of rats subjected to delayed postmortem fixation. It also scrutinizes the influence of exsanguination and cooling methods on the initiation and progression of these alterations. Twenty-four Wistar Han outbred rats (RccHan™: WIST) were sacrificed and stored either at room temperature (18–22°C) or under refrigeration (2–4°C). Necropsies were conducted at different time points postmortem (i.e., 0.5 h, 1 h, 4 h, 8 h, 12 h, 24 h, 36 h, 48 h, 7 days and 14 days). Brain sections underwent simultaneous digital evaluation by 14 pathologists until a consensus was reached on terminology, key findings, and intensity levels. Microscopic observations varied among cell types. Glial cells were similarly affected throughout the CNS and showed pericellular halo, chromatin condensation and nuclear shrinkage. Neurons showed two types of postmortem changes as most of them showed progressive shrinkage, cytoplasmic dissolution and karyorrhexis whereas others acquired a dark-neuron-like appearance. Neuronal changes showed marked differences among neuroanatomical locations. Additional postmortem changes encompassed: granulation and microcavitation in neuropil and white matter; retraction spaces; detachment of ependyma, choroid plexus, and leptomeninges. Severity of findings after 48 h at room temperature was higher than after seven days under refrigeration and similar to or slightly lower than after 14 days under refrigeration. No clear differences were observed related to the sex or weight of the animals or their exsanguination status. This work elucidates the onset and progression of autolytic changes in the brains of Wistar Han rats, offering insights to accurately identify and enhance the histopathological evaluation.

Quantifying the formation and decomposition of amyloid is a crucial issue in the development of new drugs and therapies for treating amyloidosis. The current technologies for grasping amyloid formation and decomposition include fluorescence analysis using thioflavin-T, secondary structure analysis using circular dichroism, and image analysis using atomic force microscopy or transmission electron microscopy. These technologies typically require spectroscopic devices or expensive nanoscale imaging equipment and involve lengthy analysis, which limits the rapid screening of amyloid-degrading drugs. In this study, we introduce a technology for rapidly assessing amyloid decomposition using capillary flow-based paper (CFP). Amyloid solutions exhibit gel-like physical properties due to insoluble denatured polymers, resulting in a shorter flow distance on CFP compared to pure water. Experimental conditions were established to consistently control the flow distance based on a hen-egg-white lysozyme amyloid solution. It was confirmed that as amyloid is decomposed by trypsin, the flow distance increases on the CFP. Our method is highly useful for detecting changes in the gel properties of amyloid solutions within a minute, and we anticipate its use in the rapid, large-scale screening of anti-amyloid agents in the future.

The experiment aims to monitor the amino acid content, total polyphenolic components, and antioxidant activity values of wines that have matured on yeast and non-yeast sludge. The grape varieties used in the experiment, which lasted 300 days, were (Vitis vinifera L.) Chardonnay, Riesling rhinestone, and Veltliner green. During this time, both the measured parameters and the characteristics of the wine gradually changed. The total amount of amino acids in the wines aged on yeast sludge was more than 200% greater than that found in wines aged without yeast sludge. A 30% decrease in the total polyphenolic component content was noted for wines produced with yeast lees. The antioxidant activity levels correlated with the total polyphenol content, with the levels in wines made with yeast lees on average 13% lower. The experiment showed that wines produced by these different methods have different mutagenic characteristics. Sensory analysis of the wines demonstrated that wines matured on yeast sludge have better organoleptic properties. These wines were sturdier, fuller, and more harmonious than wines aged without a yeast sludge.

ABSTRACTAims Gingival crevicular fluid (GCF) constitutes the primary growth substrate for Porphyromonas gingivalis in vivo. The goal of this work was to evaluate the growth of different strains of P. gingivalis on human serum albumin (HSA), a major constituent of GCF.Methods Growth of five different strains of P. gingivalis in the HSA medium was examined and, surprisingly, three of the strains underwent autolysis within 24 h. Comparative transcriptomic analysis was used to identify genes involved in autolysis.Results Two highly related reference strains (W50 and W83) differed dramatically in their survival when grown on HSA. Strain W83 grew fast and lysed within 24 h, while W50 survived for an additional 20 h. Differential gene expression analysis led us to a gene cluster containing enzymes involved in arginine metabolism and a gene predicted to be a lytic murein transglycosylase, which are known to play a role in autolysis. Deletion of this gene (PG0139) resulted in a mutant that did not lyse, and complementation restored the HSA lysis phenotype, indicating that this enzyme plays a central role in the autolysis of P. gingivalis.Conclusions P. gingivalis undergoes autolysis when provided with HSA as a substrate for growth.

Summary: Litopenaeus vannamei heads were autolysed at a constant temperature of 50 °C, pH 7.0 for a maximum duration of 5 h, and the antifreeze activity and physicochemical properties of the head autolysates were determined. Thermal hysteresis (TH) was used as an index for determining the antifreeze activity of the shrimp head autolysates. The highest thermal hysteresis activity was 1.82 °C which was measured in the 5 h‐shrimp head autolysate. The highest negative zeta potential value (−41.06 ± 2.08 mV) and surface hydrophobicity (295.575 ± 9.7819) were in the 5 and 1.5 h autolysate groups, respectively. Generally, <2000 Da components accounted for over 85% of the total molecular weight in all shrimp head autolysate groups. Pearson correlation analysis was used to investigate how physicochemical properties influenced the thermal hysteresis index. Although at varying degrees, the analysis confirmed that a positive correlation existed between TH activity and molecular weight, hydrophobic amino acid content, and surface hydrophobicity. A negative correlation existed between TH activity and zeta potential, and hydrophilic amino acids. The findings of our study suggest that Litopenaeus vannamei head autolysate has a potential antifreeze effect and that the physicochemical properties influence its thermal hysteresis. [ABSTRACT FROM AUTHOR]

Calpain is an intracellular cysteine protease that cleaves its specific substrates in a limited region to modulate cellular function. Calpain-1 (C1) and calpain-2 (C2) are ubiquitously expressed in mammalian cells, but calpain-3 (C3) is a skeletal muscle-specific type. In the course of calpain activation, the N-terminal regions of all three isoforms are clipped off in an intramolecular or intermolecular fashion. C1 proteolyzes C2 to promote further proteolysis, but C2 proteolyzes C1 to suspend C1 proteolysis, indicating the presence of C1–C2 reciprocal proteolysis. However, whether C3 is involved in the calpain proteolysis network is unclear. To address this, we examined whether GFP-tagged C3:C129S (GFP-C3:CS), an inactive protease form of C3, was a substrate for C1 or C2 in HEK cells. Intriguingly, the N-terminal region of C3:CS was cleaved by C1 and C2 at the site identical to that of the C3 autoproteolysis site. Furthermore, the N-terminal clipping of C3:CS by C1 and C2 was observed in mouse skeletal muscle lysates. Meanwhile, C3 preferentially cleaved the N-terminus of C1 over that of C2, and the sizes of these cleaved proteins were identical to their autoproteolysis forms. Our findings suggest an elaborate inter-calpain network to prime and suppress proteolysis of other calpains. [ABSTRACT FROM AUTHOR]

This study aimed to examine the oxygenation effects on sea cucumber autolysis by comparing the condition between the oxygen-addition group and air-addition group during storage and transportation. Sea cucumbers were exposed to 0, 6.25, 12.5, 25, 50, and 100% oxygen addition for 6 days, and the levels of ammonia released were measured to monitor the status of the sea cucumbers. Results showed that a general decline in ammonia release from 0 to 25% oxygen, then an increase again from 25 to 100% oxygen. Hence, the oxygen level of 25% was found to be optimal in maintaining the sea cucumber health during storage. Subsequently, 25% oxygen and air treatments on sea cucumber were compared, and results showed sea cucumbers in the oxygen group exhibited better morphology, and got 1.23 times better sensory scores than that of the air-treated group. The body-wall hardness of the oxygen group was 2.17-fold higher than that of the air treatment group. The respiratory tree and intestine microstructure tests showed the air-treated sea cucumber group suffered from autolysis after storage, showing visible tissue atrophy and disintegration of surface villi. By contrast, the oxygen-treated group exhibited only slight autolysis with largely intact tissue structure. Various gene expression levels for key enzymes, including superoxide dismutase, glutathione peroxidase, acid phosphatase, alkaline phosphatase, lysozyme, succinate dehydrogenase, lactate dehydrogenase, Alpha-amylase, peptidase, trypsin, and heat shock protein 70 (Hsp70), were determined for oxygen and air treated sea cucumbers after 6-day storage. Results suggested that oxygen-treated sea cucumbers maintained good immune defense, oxidation resistance, and digestive capacity, while the air-treated sea cucumbers did not. HSP70 expression level in the oxygen-treated group was 13.5-fold higher than the fresh sea cucumber group, indicating that oxygen inhibited/delayed sea cucumber autolysis mainly by preventing protein denaturation via the improvement of HSP70 expression level. [ABSTRACT FROM AUTHOR]

The presence of lactic acid bacteria (LAB) as probiotics in the harsh intestinal environment is usually transient. In recent years, quorum-sensing (QS), a signalling molecule-based form of bacterial communication, has attracted increasing attention due to its vital role in regulating LAB properties that support colonisation, such as acid resistance, adhesion, and biofilm formation. QS is also widely involved in the autolysis of and bacteriocin production by LAB, processes that are essential for the application of these species as probiotics or industrial starter cultures. Base on introducing LAB's QS systems, this review discusses the factors that may affect QS, the effect of QS on the LAB's intestinal colonisation, and the possible interactions mediated by QS between probiotics and the gut microbiome. [ABSTRACT FROM AUTHOR]

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Biobutanol is a valuable biochemical and one of the most promising biofuels. Clostridium saccharoperbutylacetonicum N1-4 is a hyperbutanol-producing strain. However, its strong autolytic behavior leads to poor cell stability, especially during continuous fermentation, thus limiting the applicability of the strain for long-term and industrial-scale processes. In this study, we aimed to evaluate the role of autolysin genes within the C. saccharoperbutylacetonicum genome related to cell autolysis and further develop more stable strains for enhanced butanol production. First, putative autolysin-encoding genes were identified in the strain based on comparison of amino acid sequence with homologous genes in other strains. Then, by overexpressing all these putative autolysin genes individually and characterizing the corresponding recombinant strains, four key genes were pinpointed to be responsible for significant cell autolysis activities. Further, these key genes were deleted using CRISPR-Cas9. Fermentation characterization demonstrated enhanced performance of the resultant mutants. Results from this study reveal valuable insights concerning the role of autolysins for cell stability and solvent production, and they provide an essential reference for developing robust strains for enhanced biofuel and biochemical production.IMPORTANCE Severe autolytic behavior is a common issue in Clostridium and many other microorganisms. This study revealed the key genes responsible for the cell autolysis within Clostridium saccharoperbutylacetonicum, a prominent platform for biosolvent production from lignocellulosic materials. The knowledge generated in this study provides insights concerning cell autolysis in relevant microbial systems and gives essential references for enhancing strain stability through rational genome engineering.

In order to strengthen the high-value processing and utilization of marine by-products, shrimp by-products were used in this study. The autolysis reaction was carried out in a water bath at 50 ℃ and pH(7.81~7.83), then the enzymatic hydrolysate was heated in water bath at 95 ℃ for 20 min to inactivate endogenous enzymes. This paper studied the changes in the polypeptide composition of the enzymatic hydrolysis products during the process, and screened the antifreeze peptide sequences based on the activity prediction platform, and provided a method for screening active peptides with high efficiency. When the autolysis treatment was 0~3 h, the content of degree of hydrolysis (DH) and TCA soluble peptides in the enzymatic hydrolyzate increased sharply, reaching 49.8% and 26.1 mg/g, respectively, and then the growth rate slowed down. 1301 peptides were detected in the 0.5 h enzymatic hydrolysis product (A-0.5), and 197 in the 3 h enzymatic hydrolysis product (A-3). The content of peptides greater than 1600 Da in A-0.5 reached 69.5%, while the peptides in A-3 were dominated by 600~1600 Da. Based on the activity prediction platform Cryoprotect, 7 sequences of QVHPDTGISS, GYGCARPNYPGV, TTGEVCDSGDGVTH, EQICINFCNEK, DEYEESGPGIVH, DIDNDGFLDK and DIDNNGFLDK were screened as antifreeze peptides, and the source of the peptides was obtained by enzyme cleavage simulation.

To better understand the metabolism in industrial lactic acid fermentation by Bacillus coagulans, the lactic acid fermentation characteristics with mixed carbon sources were studied under varied aeration, pH, and neutralizer conditions in laboratory-scale bioreactor, and the effects of metal ions and osmotic pressure on the autolysis of B. coagulans under starvation were conducted. The results showed that the lactic acid fermentation by B. coagulans using glucose+trehalose as the mixed carbon source showed a significant carbon catabolite repression (CCR), and the fermentation process could be divided into glucose consumption phase (phase I), organic acids consumption phase (phase II) and trehalose consumption phase (phase III). Differents fermentation conditions had less of an impact on cell growth and lactic acid production at phase I, but had a considerable impact on phase III. In the phase III, the highest trehalose consumption rate and lactic acid productivity appeared at 7.2 L/h (0.03 vvm) ventilation. The rates of sugar consumption and lactic acid production were higher at pH6.5 than that at pH6.0, while nearly no trehalose consumption and lactic acid production were observed at pH5.5. Compared with NaOH, when Ca(OH)2 was used as a neutralizer at pH6.5, the trehalose utilization rate and lactic acid production rate were enhanced by 21.0% and 28.3%, respectively. It was found that Ca2+ and Mg2+ alleviated autolysis, while Na+ had some benefits in maintaining the activity of cells. The results of this paper would lay the foundation for studying the mechanism of metabolic shift during lactic acid fermentation by B. coagulans in mixed carbon sources.

TsaB/YeaZ represents a promising target for novel antibacterial agents due to its indispensable role in bacterial survival, high conservation within bacterial species, and absence of eukaryotic homologs. Previous studies have elucidated the role of the essential staphylococcal protein, TsaB/YeaZ, in binding DNA to mediate the transcription of the ilv-leu operon, responsible for encoding key enzymes involved in the biosynthesis of branched-chain amino acids—namely isoleucine, leucine, and valine (ILV). However, the regulation of ILV biosynthesis does not account for the essentiality of TsaB/YeaZ for bacterial growth. In this study, we investigated the impact of TsaB/YeaZ depletion on bacterial morphology and gene expression profiles using electron microscopy and deep transcriptomic analysis, respectively. Our results revealed significant alterations in bacterial size and surface smoothness upon TsaB/YeaZ depletion. Furthermore, we pinpointed specific genes and enriched biological pathways significantly affected by TsaB/YeaZ during the early and middle exponential phases and early stationary phases of growth. Crucially, our research uncovered a regulatory role for TsaB/YeaZ in bacterial autolysis. These discoveries offer fresh insights into the multifaceted biological functions of TsaB/YeaZ within S. aureus.

Objective: This study aimed to explore the changes of polypeptides and free amino acids in Acetes chinensis before and after autolysis. Methods: The optimal pH and temperature of the endogenous protease of the A. chinensis were determined and the autolysis conditions were optimized. Then changes of a polypeptide, amino acid and molecular weight in the product before and after autolysis were studied under the optimal conditions. Results: The optimum temperature and pH of endogenous protease were 45 ℃ and 8.0 respectively. Under the optimal autolysis conditions of pH 8.0, temperature 40 ℃, and reaction time 4 h, the polypeptide concentration of A. chinensis surimi was 10.36 mg/mL. The content of total free amino acids, essential amino acids and hydrophobic amino acids increased, the proportion of bitter amino acids increased by （4.54±0.02）%, while the proportion of umami amino acids and sweet amino acids decreased by （3.46±0.02）% and （1.78±0.01）% respectively. The proportion of degradation products with molecular weight less than 1 000 Da increased from 70% to 87%. Conclusion: Autolysis technology can degrade the protein of A. chinensis and release small molecule peptides and amino acids.

Iron is known to accumulate in neurological disorders, so a careful balance of the iron concentration is essential for healthy brain functioning. An imbalance in iron homeostasis could arise due to the dysfunction of proteins involved in iron homeostasis. Here, we focus on ferritin—the primary iron storage protein of the brain. In this study, we aimed to improve a method to measure ferritin-bound iron in the human post-mortem brain, and to discern its distribution in particular cell types and brain regions. Though it is known that glial cells and neurons differ in their ferritin concentration, the change in the number and distribution of iron-filled ferritin cores between different cell types during autolysis has not been revealed yet. Here, we show the cellular and region-wide distribution of ferritin in the human brain using state-of-the-art analytical electron microscopy. We validated the concentration of iron-filled ferritin cores to the absolute iron concentration measured by quantitative MRI and inductively coupled plasma mass spectrometry. We show that ferritins lose iron from their cores with the progression of autolysis whereas the overall iron concentrations were unaffected. Although the highest concentration of ferritin was found in glial cells, as the total ferritin concentration increased in a patient, ferritin accumulated more in neurons than in glial cells. Summed up, our findings point out the unique behaviour of neurons in storing iron during autolysis and explain the differences between the absolute iron concentrations and iron-filled ferritin in a cell-type-dependent manner in the human brain. The rate of loss of the iron-filled ferritin cores during autolysis is higher in neurons than in glial cells. [ABSTRACT FROM AUTHOR]