EcCas6e-based antisense crRNA for gene repression and RNA editing in microorganisms.

Precise gene regulation and programmable RNA editing are vital RNA-level regulatory mechanisms. Gene repression tools grounded in small non-coding RNAs, microRNAs, and CRISPR-dCas proteins, along with RNA editing tools anchored in Adenosine Deaminases acting on RNA (ADARs), have found extensive application in molecular biology and cellular engineering. Here, we introduced a novel approach wherein we developed an EcCas6e mediated crRNA-mRNA annealing system for gene repression in Escherichia coli and RNA editing in Saccharomyces cerevisiae. We found that EcCas6e possesses inherent RNA annealing ability attributed to a secondary positively charged cleft, enhancing crRNA-mRNA hybridization and stability. Based on this, we demonstrated that EcCas6e, along with its cognate crRNA repeat containing a complementary region to the ribosome binding site of a target mRNA, effectively represses gene expression up to 25-fold. Furthermore, we demonstrated that multiple crRNAs can be easily assembled and can simultaneously target up to 13 genes. Lastly, the EcCas6e-crRNA system was developed as an RNA editing tool by fusing it with the ADAR2 deaminase domain. The EcCas6e-crRNA mediated gene repression and RNA editing tools hold broad applications for research and biotechnology.

The association between smoking cessation and lifestyle/genetic variant rs6265 among the adult population in Taiwan.

Recent studies showed significant associations between socio-demographic, lifestyle factors, polymorphic variant rs6265, and smoking cessation behaviours. We examined rs6265 TT, TC and CC genotypes and their association with socio-demographic and other variables, including mental health status, drinking, exercise, and smoking behaviour among Taiwanese adults. Data on rs6265 were retrieved from the Taiwan Biobank, which contained genetic data collected between 2008 to 2019 from 20,584 participants (aged 30-70 years). Participants who smoked for more than 6 months prior to enrolment were categorized as smokers. If they had smoked and later quit for more than 6 months, they were classified as former smokers. Information regarding drinking, exercise, depression, and bipolar disorder were obtained through questionnaires and were categorized as either as affirmative (yes) or negative (no) responses. In contrast to previous studies, we found that the association between the polymorphism rs6265 and smoking behaviour was not significant (P-value = 0.8753). Males with lower education levels, young persons, and alcohol drinkers showed significant smoking behaviours (P-value < .0001). This population-based study indicates that rs6265 has no significant correlations with smoking cessation behaviour among adults in Taiwan.

Characterization and designing of an SAM riboswitch to establish a high-throughput screening platform for SAM overproduction in Saccharomyces cerevisiae.

S-adenosyl- l-methionine (SAM) is a high-value compound widely used in the treatment of various diseases. SAM can be produced through fermentation, but further enhancing the microbial production of SAM requires novel high-throughput screening methods for rapid detection and screening of mutant libraries. In this work, an SAM-OFF riboswitch capable of responding to the SAM concentration was obtained and a high-throughput platform for screening SAM overproducers was established. SAM synthase was engineered by semirational design and directed evolution, which resulted in the SAM2S203F,W164R,T251S,Y285F,S365R mutant with almost twice higher catalytic activity than the parental enzyme. The best mutant was then introduced into Saccharomyces cerevisiae BY4741, and the resulting strain BSM8 produced a sevenfold higher SAM titer in shake-flask fermentation, reaching 1.25 g L-1 . This work provides a reference for designing biosensors to dynamically detect metabolite concentrations for high-throughput screening and the construction of effective microbial cell factories.

Novel nitrogen mustard-artemisinin hybrids with potent anti-leukemia action through DNA damage and activation of GPx.

The incidence of various types of cancers is increasing every year. Among these, leukemia is extremely common, and thus, developing novel drugs to combat leukemia is crucial. In this study, we designed and synthesized several hybrids and obtained a new lead molecule 5a, with a strong therapeutic effect on leukemia. The results indicated that most hybrids effectively inhibited the growth of leukemia cells, HCT-116, and A549 cancer cells with an IC50 of <10 µM. Among these hybrids, 5a and 4h showed significant anticancer activity against CCRF-CEM, with IC50 values of 0.895 µM and 0.555 µM, respectively. Particularly, 5a had lower toxicity to L02 than chlorambucil (CLB) and doxorubicin (Dox), and the high selectivity was also reflected in the normal human B lymphoblast cell line (IM9). Upon investigating the mechanism of action, we found that 5a downregulated Bcl-2 and caused DNA double-stranded breaks (DSBs) to induce several genotoxic stress responses. The results of the flow cytometry assay showed that 5a was a non-specific molecule in the cell cycle. Furthermore, 5a did not affect total ROS levels but significantly improved the activity of glutathione peroxidase (GPx). Preliminary studies showed that nitrogen mustard exerted an efficient effect, and 5a can combine the advantages of artemisinin and nitrogen mustard and exhibit effects superior to either. This study showed that 5a should be further investigated as a therapeutic compound against leukemia.

Heterologous biosynthesis of taraxerol by engineered Saccharomyces cerevisiae.

Taraxerol is an oleanane-type pentacyclic triterpenoid compound distributed in many plant species that has good effects on the treatment of inflammation and tumors. However, the taraxerol content in medicinal plants is low, and chemical extraction requires considerable energy and time, so taraxerol production is a problem. It is a promising strategy to produce taraxerol by applying recombinant microorganisms. In this study, a Saccharomyces cerevisiae strain WKde2 was constructed to produce taraxerol with a titer of 1.85 mg·l-1, and the taraxerol titer was further increased to 12.51 mg·l-1 through multiple metabolic engineering strategies. The endoplasmic reticulum (ER) size regulatory factor INO2, which was reported to increase squalene and cytochrome P450-mediated 2,3-oxidosqualene production, was overexpressed in this study, and the resultant strain WTK11 showed a taraxerol titer of 17.35 mg·l-1. Eventually, the highest reported titer of 59.55 mg·l-1 taraxerol was achieved in a 5 l bioreactor. These results will serve as a general strategy for the production of other triterpenoids in yeast.

Metabolic Engineering of Saccharomyces cerevisiae for Heterologous Carnosic Acid Production.

Carnosic acid (CA), a phenolic tricyclic diterpene, has many biological effects, including anti-inflammatory, anticancer, antiobesity, and antidiabetic activities. In this study, an efficient biosynthetic pathway was constructed to produce CA in Saccharomyces cerevisiae. First, the CA precursor miltiradiene was synthesized, after which the CA production strain was constructed by integrating the genes encoding cytochrome P450 enzymes (P450s) and cytochrome P450 reductase (CPR) SmCPR. The CA titer was further increased by the coexpression of CYP76AH1 and SmCPR ∼t28SpCytb5 fusion proteins and the overexpression of different catalases to detoxify the hydrogen peroxide (H2O2). Finally, engineering of the endoplasmic reticulum and cofactor supply increased the CA titer to 24.65 mg/L in shake flasks and 75.18 mg/L in 5 L fed-batch fermentation. This study demonstrates that the ability of engineered yeast cells to synthesize CA can be improved through metabolic engineering and synthetic biology strategies, providing a theoretical basis for microbial synthesis of other diterpenoids.

Construction and optimization of Saccharomyces cerevisiae for synthesizing forskolin.

Forskolin, one of the primary active metabolites of labdane-type diterpenoids, exhibits significant medicinal value, such as anticancer, antiasthmatic, and antihypertensive activities. In this study, we constructed a Saccharomyces cerevisiae cell factory that efficiently produced forskolin. First, a chassis strain that can accumulate 145.8 mg/L 13R-manoyl oxide (13R-MO), the critical precursor of forskolin, was constructed. Then, forskolin was produced by integrating CfCYP76AH15, CfCYP76AH11, CfCYP76AH16, ATR1, and CfACT1-8 into the 13R-MO chassis with a titer of 76.25 µg/L. We confirmed that cytochrome P450 enzymes (P450s) are the rate-limiting step by detecting intermediate metabolite accumulation. Forskolin production reached 759.42 µg/L by optimizing the adaptations between CfCYP76AHs, t66CfCPR, and t30AaCYB5. Moreover, multiple metabolic engineering strategies, including regulation of the target genes' copy numbers, amplification of the endoplasmic reticulum (ER) area, and cofactor metabolism enhancement, were implemented to enhance the metabolic flow to forskolin from 13R-MO, resulting in a final forskolin yield of 21.47 mg/L in shake flasks and 79.33 mg/L in a 5 L bioreactor. These promising results provide guidance for the synthesis of other natural terpenoids in S. cerevisiae, especially for those containing multiple P450s in their synthetic pathways. KEY POINTS: • The forskolin biosynthesis pathway was optimized from the perspective of system metabolism for the first time in S. cerevisiae. • The adaptation and optimization of CYP76AHs, t66CfCPR, and t30AaCYB5 promote forskolin accumulation, which can provide a reference for diterpenoids containing complex pathways, especially multiple P450s pathways. • The forskolin titer of 79.33 mg/L is the highest production currently reported and was achieved by fed-batch fermentation in a 5 L bioreactor.

Protective effects and mechanism of coenzyme Q10 and vitamin C on doxorubicin-induced gastric mucosal injury and effects of intestinal flora.

Doxorubicin (Dox) is widely used to the treatment of cancer, however, it could cause damage to gastric mucosa. To investigate the protective effects and related mechanisms of coenzyme Q10 (CoQ10) and vitamin C (VC) on Dox-induced gastric mucosal injury, we presented the survey of the 4 groups of the rats with different conditions. The results showed Dox treatment significantly induced GES-1 apoptosis, but preconditioning in GES-1 cells with VC or CoQ10 significantly inhibited the Dox-induced decrease and other harm effects, including the expression and of IκKß, IκBα, NF-κB/p65 and tumor necrosis factor (TNF-α) in GES-1 cells. Moreover, high-throughput sequencing results showed Dox treatment increased the number of harmful gut microbes, and CoQ10 and VC treatment inhibited this effect. CoQ10 and VC treatment inhibits Dox-induced gastric mucosal injury by inhibiting the activation of the IkKB/IκBα/NF-κB/p65/TNF-α pathway, promoting anti-inflammatory effects of gastric tissue and regulating the composition of the intestinal flora.

MicroRNA-29b-3p Inhibits the Migration and Invasion of Gastric Cancer Cells by Regulating the Autophagy-Associated Protein MAZ.

PURPOSE: The purpose of this study was to investigate the relationship between microRNA-29b-3p (miR-29b-3p) and myc-associated zinc finger protein (MAZ) expression and the effects of this interaction on the proliferation, migration, and invasion of gastric cancer cells. METHODS: qPCR and Western blots were used to detect the expression of miR-29b-3p and MAZ. The dual luciferase reporter gene system was used to explore whether MAZ is the target of miR-29b-3p. Cell function experiments and a mouse tumorigenesis model were used to determine the effects of miR-29b-3p overexpression and MAZ depletion on proliferation, migration, and invasion in gastric cancer cell lines and on tumor growth. RESULTS: The expression level of miR-29b-3p was low and the expression level of MAZ was high in gastric cancer cells compared with normal human gastric mucosal epithelial cells. MAZ was the target gene of miR-29b-3p. The upregulation of miR-29b-3p reduces the expression of MAZ. Overexpression of miR-29b-3p and downregulation of MAZ inhibited the proliferation and migration of cancer cells and induced apoptosis by controlling the expression of autophagy-related proteins. MiR-29b-3p mimics inhibit tumor growth in mice. CONCLUSION: MiR-29b-3p inhibits the migration and invasion of gastric cancer cells by regulating the autophagy-related protein MAZ.

Structural elucidation and antidiabetic activity of fucosylated chondroitin sulfate from sea cucumber Stichopus japonicas.

A fucosylated chondroitin sulfate was isolated from the body wall of sea cucumber Stichopus japonicus (FCSsj), whose structure was characterized by NMR spectroscopy and HILIC-FTMS. At the ratio of 1.00:0.26:0.65, three fucosyl residues were found: 2,4-disulfated-fucose (Fuc2,4S), 4-sulfated-fucose (Fuc4S) and 3,4-disulfated-fucose (Fuc3,4S), which were only linked to the O-3 of glucuronic acid residues (GlcA). Besides mono-fucosyl moieties, di-fucosyl branches, namely Fuc2,4Sα(1→3)Fuc4S, were also found to be attached to the O-3 of GlcA. The antidiabetic activity of FCSsj was evaluated using glucosamine induced insulin resistant (IR) Hep G2 cells in vitro. It was found that FCSsj significantly promoted the glucose uptake and glucose consumption of IR-Hep G2 cells in a dose-dependent manner, and could alleviate the cell damage. Furthermore, FCSsj could promote the glycogen synthesis in the glucosamine-induced IR-Hep G2 cells. These results provided a supplement for studying the antidiabetic activity of FCSsj.

Progress in heterologous biosynthesis of forskolin.

Forskolin, a class of labdane-type diterpenoid, has significant medicinal value in anticancer, antiasthmatic, antihypertensive, and heart-strengthening treatments. The main source of natural forskolin is its extraction from the cork tissue of the root of Coleus forskohlii. However, conventional modes of extraction pose several challenges. In recent years, the construction of microbial cell factories to produce medicinal natural products via synthetic biological methods has effectively solved the current problems and is a research hotspot in this field. This review summarizes the recent progress in the heterologous synthesis of forskolin via synthetic biological technology, analyzes the current challenges, and proposes corresponding strategies.

Application of marine natural products in drug research.

New diseases are emerging as the environment changes, so drug manufacturers are always on the lookout for new resources to develop effective and safe drugs. In recent years, many bioactive substances have been produced in the marine environment, which represents an alternative resource for new drugs used to combat major diseases such as cancer or inflammation. Many marine-derived medicinal substances are in preclinical or early stage of clinical development, and some marine drugs have been put on the market, such as ET743 (Yondelis®). This review presents the sources, activities, mechanisms of action and syntheses of bioactive substances based on marine natural products in clinical trials and on the market, which is helpful to understand the progress of drug research by application of marine natural products.

Interactive association between dietary fat and sex on CDH13 cg02263260 methylation.

BACKGROUND: DNA methylation of Cadherin 13 (CDH13), a tumor suppressor gene is associated with gene repression and carcinogenesis. We determined the relation of dietary fat and sex with CDH13 cg02263260 methylation in Taiwanese adults. METHODS: Data of 870 eligible participants (430 men and 440 women) between 30 and 70 years were obtained from the Taiwan Biobank (TWB) database. The association of dietary fat and sex with CDH13 cg02263260 methylation was determined using multiple linear regression. RESULTS: The association between sex and cg02263260 methylation was significant: beta-coefficient (ß) = 0.00532; 95% confidence interval (CI) = 0.00195-0.00868. Moreover, the interaction between sex and dietary fat on cg02263260 methylation was significant (P-value = 0.0145). After stratification by sex, the association of dietary fat with cg02263260 methylation was significant only in women. Specifically, high dietary fat was positively associated with cg02263260 methylation in women (ß = 0.00597; 95% CI = 0.00061-0.01133) and the test for trend was significant (P-value = 0.0283). CONCLUSION: High fat intake was significantly associated with higher cg02263260 methylation in women and the test for trend was significant. These findings suggest that the association of fat intake and CDH13 cg02263260 might vary by sex and CDH13 cg02263260 methylation levels in women might increase as fat intake increases.

Novel artemisinin derivatives with potent anticancer activities and the anti-colorectal cancer effect by the mitochondria-mediated pathway.

Many artemisinin derivatives have good inhibitory effects on malignant tumors. In this work, a novel series of artemisinin derivatives containing piperazine and fluorine groups were designed and synthesized and their structures were confirmed by 1H NMR, 13C NMR and HRMS technologies. The in vitro cytotoxicity against various cancer cell lines was evaluated. Among the derivatives, compound 12h was found to exhibit not only the best activity against HCT-116 cells (IC50 = 0.12 ± 0.05 µM), but also low toxicity against normal cell line L02 (IC50 = 12.46 ± 0.10 µM). The mechanisms study revealed that compound 12h caused the cell cycle arrest in G1 phase, induced apoptosis in a concentration-dependent manner, significantly reduced mitochondrial membrane potential, increased intracellular ROS and Ca2+ levels, up-regulated the expression of Bax, cleaved caspase-9, cleaved caspase-3, and down-regulated the expression of Bcl-2 protein. A series of analyses confirmed that 12h can inhibit HCT-116 cells migration and induce apoptosis by a mechanism of the mitochondria-mediated pathway in the HCT-116 cell line. The present work indicates that compound 12h may merit further investigation as a potential therapeutic agent for colorectal cancer.

AHRR cg05575921 methylation in relation to smoking and PM2.5 exposure among Taiwanese men and women.

BACKGROUND: Polycyclic aromatic hydrocarbon (PAH)-rich substances like cigarette smoke and PM2.5 induce aryl hydrocarbon receptor (AHR)-mediated aryl hydrocarbon receptor repressor (AHRR) methylation. AHRR cg05575921 and coagulation factor II (thrombin) receptor-like 3 (F2RL3) cg03636183 methylation patterns are well-established biomarkers for smoking. Even though AHRR cg05575921 methylation has recently been associated with PM2.5, the interaction between smoking and PM2.5 on AHRR methylation is yet to be fully explored. We evaluated AHRR and F2RL3 CpG sites to identify potential significant markers in relation to PM2.5 and smoking in Taiwanese adults. METHODS: DNA methylation and smoking data of 948 participants aged 30-70 years were obtained from the Taiwan Biobank Database (2008-2015), while PM2.5 data were obtained from the Air Quality Monitoring Database (2006-2011). RESULTS: Smoking and PM2.5 were independently associated with hypomethylation (lower levels) of AHRR cg05575921, AHRR cg23576855, F2RL3 cg03636183, and F2LR3 cg21911711 after multiple-comparison correction (Bonferroni P < 0.00028409). Cg05575921 was the most hypomethylated AHRR CpG site, while cg03636183 was the most hypomethylated F2RL3 CpG site. Overall, cg05575921 was the most hypomethylated CpG site: ß = - 0.03909, P < 0.0001; - 0.17536, P < 0.0001 for former and current smoking, respectively (P-trendsmoking < 0.0001) and - 0.00141, P < 0.0001 for PM2.5. After adjusting for F2RL3 cg03636183, smoking and PM2.5 remained significantly associated with cg05575921 hypomethylation: ß - 0.02221, P < 0.0001; - 0.11578, P < 0.0001 for former and current smoking, respectively (P-trendsmoking < 0.0001) and - 0.0070, P = 0.0120 for PM2.5. After stratification by sex, smoking and PM2.5 remained associated (P < 0.05) with cg05575921 hypomethylation in both men (ß = - 0.04274, - 0.17700, and - 0.00163 for former smoking, current smoking, and PM2.5, respectively) and women (ß = - 0.01937, - 0.17255, and - 0.00105 for former smoking, current smoking, and PM2.5, respectively). After stratification by residential area, former and current smoking remained associated (P < 0.05) with cg05575921 hypomethylation: ß = - 0.03918 and - 0.17536, respectively (P-trendsmoking < 0.0001). Living in the central and southern areas was also associated (P < 0.05) with cg05575921 hypomethylation: ß = - 0.01356 and - 0.01970, respectively (P-trendarea < 0.0001). CONCLUSION: Smoking and PM2.5 were independently associated with hypomethylation of cg05575921, cg23576855, cg03636183, and cg21911711. The most hypomethylated CpG site was cg05575921 and its association with smoking and PM2.5 was dose-dependent.

Promotion of compound K production in Saccharomyces cerevisiae by glycerol.

BACKGROUND: Ginsenoside compound K (CK), one of the primary active metabolites of protopanaxadiol-type ginsenosides, is produced by the intestinal flora that degrade ginseng saponins and exhibits diverse biological properties such as anticancer, anti-inflammatory, and anti-allergic properties. However, it is less abundant in plants. Therefore, enabling its commercialization by construction of a Saccharomyces cerevisiae cell factory is of considerable significance. RESULTS: We induced overexpression of PGM2, UGP1, and UGT1 genes in WLT-MVA5, and obtained a strain that produces ginsenoside CK. The production of CK at 96 h was 263.94 ± 2.36 mg/L, and the conversion rate from protopanaxadiol (PPD) to ginsenoside CK was 64.23 ± 0.41%. Additionally, it was observed that the addition of glycerol was beneficial to the synthesis of CK. When 20% glucose (C mol) in the YPD medium was replaced by the same C mol glycerol, CK production increased to 384.52 ± 15.23 mg/L, which was 45.68% higher than that in YPD medium, and the PPD conversion rate increased to 77.37 ± 3.37% as well. As we previously observed that ethanol is beneficial to the production of PPD, ethanol and glycerol were fed simultaneously in the 5-L bioreactor fed fermentation, and the CK levels reached 1.70 ± 0.16 g/L. CONCLUSIONS: In this study, we constructed an S. cerevisiae cell factory that efficiently produced ginsenoside CK. Glycerol effectively increased the glycosylation efficiency of PPD to ginsenoside CK, guiding higher carbon flow to the synthesis of ginsenosides and effectively improving CK production. CK production attained in a 5-L bioreactor was 1.7 g/L after simultaneous feeding of glycerol and ethanol.

Production of Triterpene Ginsenoside Compound K in the Non-conventional Yeast Yarrowia lipolytica.

Compound K (CK) is a rare, tetracyclic, triterpenoid compound with important medical properties, such as antitumor and anti-inflammatory activities. Herein, an efficient biosynthetic pathway of CK was constructed in metabolically engineered Yarrowia lipolytica for the first time, and the engineered strain, YL-CK0, produced 5.1 mg/L CK. The production of CK was further increased by 5.96-fold to 30.4 mg/L with overexpression of key genes in the MVA pathway and fusion of cytochrome P450 monooxygenase (PPDS) and NADPH-P450 reductase. Finally, 161.8 mg/L CK production was achieved by fed-batch fermentation in a 5 L fermenter using the strain YL-MVA-CK. To the best of our knowledge, this is the first report on heterologous CK synthesis with the highest titer in Y. lipolytica. This study demonstrates the feasibility of producing high-value triterpenoid compounds using Y. lipolytica as a platform.

Suitable extracellular oxidoreduction potential inhibit rex regulation and effect central carbon and energy metabolism in Saccharopolyspora spinosa.

BACKGROUND: Polyketides, such as spinosad, are mainly synthesized in the stationary phase of the fermentation. The synthesis of these compounds requires many primary metabolites, such as acetyl-CoA, propinyl-CoA, NADPH, and succinyl-CoA. Their synthesis is also significantly influenced by NADH/NAD+. Rex is the sensor of NADH/NAD+ redox state, whose structure is under the control of NADH/NAD+ ratio. The structure of rex controls the expression of many NADH dehydrogenases genes and cytochrome bd genes. Intracellular redox state can be influenced by adding extracellular electron acceptor H2O2. The effect of extracellular oxidoreduction potential on spinosad production has not been studied. Although extracellular oxidoreduction potential is an important environment effect in polyketides production, it has always been overlooked. Thus, it is important to study the effect of extracellular oxidoreduction potential on Saccharopolyspora spinosa growth and spinosad production. RESULTS: During stationary phase, S. spinosa was cultured under oxidative (H2O2) and reductive (dithiothreitol) conditions. The results show that the yield of spinosad and pseudoaglycone increased 3.11 fold under oxidative condition. As H2O2 can be served as extracellular electron acceptor, the ratios of NADH/NAD+ were measured. We found that the ratio of NADH/NAD+ under oxidative condition was much lower than that in the control group. The expression of cytA and cytB in the rex mutant indicated that the expression of these two genes was controlled by rex, and it was not activated under oxidative condition. Enzyme activities of PFK, ICDH, and G6PDH and metabolites results indicated that more metabolic flux flow through spinosad synthesis. CONCLUSION: The regulation function of rex was inhibited by adding extracellular electron acceptor-H2O2 in the stationary phase. Under this condition, many NADH dehydrogenases which were used to balance NADH/NAD+ by converting useful metabolites to useless metabolites and unefficient terminal oxidases (cytochrome bd) were not expressed. So lots of metabolites were not waste to balance. As a result, un-wasted metabolites related to spinosad and PSA synthesis resulted in a high production of spinosad and PSA under oxidative condition.

Kinetic analysis and modeling of daptomycin batch fermentation by Streptomyces roseosporus.

In this study, Streptomyces roseosporus was subjected to helium-neon (He-Ne) laser (632.8 nm) irradiation to improve the production ability of extracellular antibiotic daptomycin. Under the optimum irradiation dosage of 18 mW for 22 min, a stable positive mutant strain S. roseosporus LC-54 was obtained. The maximum A21978C (daptomycin is a semisynthetic antimicrobial substance derived from the A21978C complex) yield of this mutant strain was 296 mg/l, which was 146% higher than that of the wild strain. The mutant strain grew more quickly and utilized carbohydrate sources more efficiently than the wild strain. The batch culture kinetics was investigated in a 7 l bioreactor. The logistic equation for growth, the Luedeking-Piret equation for daptomycin production, and Luedeking-Piret-like equations for carbon substrate consumption were established. This model appeared to provide a reasonable description for each parameter during the growth phase and fitted fairly well with the experiment data.