1
|
Berenjian A, Mahdinia E, Demirci A. Sustainable menaquinone-7 production through continuous fermentation in biofilm bioreactors. Bioprocess Biosyst Eng 2024; 47:1107-1116. [PMID: 38864863 DOI: 10.1007/s00449-024-03040-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024]
Abstract
Menaquinone-7 (MK-7), a vital vitamin with numerous health benefits, is synthesized and secreted extracellularly by the formation of biofilm, dominantly in Bacillus strains. Our team developed an innovative biofilm reactor utilizing Bacillus subtilis natto cells to foster biofilm growth on plastic composite supports to produce MK-7. Continuous fermentation in biofilm reactors offers a promising strategy for achieving sustainable and efficient production of Menaquinone-7 (MK-7). Unlike conventional batch fermentation, continuous biofilm reactors maintain a steady state of operation, which reduces resource consumption and waste generation, contributing to sustainability. By optimizing fermentation conditions, MK-7 production was significantly enhanced in this study, demonstrating the potential for sustainable industrial-scale production. To determine the optimal operational parameters, various dilution rates were tested. These rates were selected based on their potential to enhance nutrient supply and biofilm stability, thereby improving MK-7 production. By carefully considering the fermentation conditions and systematically varying the dilution rates, MK-7 production was significantly enhanced during continuous fermentation. The MK-7 productivity was found to increase from 0.12 mg/L/h to 0.33 mg/L/h with a dilution rate increment from 0.007 to 0.042 h-1). This range was chosen to explore the impact of various nutrient supply rates on MK-7 production and to identify the optimal conditions for maximizing productivity. However, a further increase in the dilution rate to 0.084 h-1 led to reduced productivity at approximately 0.16 mg/L/h, likely due to insufficient retention time for effective biofilm formation. Consequently, a dilution rate of 0.042 h-1 exhibited the highest productivity of 0.33 mg/L/h, outperforming all investigated dilution rates and demonstrating the critical balance between nutrient supply and retention time in continuous fermentation. These findings validate the feasibility of operating continuous fermentation at a 0.084 h-1 dilution rate, corresponding to a 48 h retention time, to achieve the highest MK-7 productivity compared to conventional batch fermentation. The significant advancements achieved in enhancing Menaquinone-7 (MK-7) productivity through continuous fermentation at optimal dilution rates in the present work indicate promising prospects for even greater efficiency and sustainability in MK-7 production through future developments.
Collapse
Affiliation(s)
- Aydin Berenjian
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO, 80523, USA
- Department of Agricultural and Biological Engineering, 221 Agricultural Engineering Building, Pennsylvania State University, University Park, PA, 16802, USA
| | - Ehsan Mahdinia
- Stack Family Center for Biopharmaceutical Education and Training, Albany College of Pharmacy and Health Sciences, Albany, NY, 12203, USA
| | - Ali Demirci
- Department of Agricultural and Biological Engineering, 221 Agricultural Engineering Building, Pennsylvania State University, University Park, PA, 16802, USA.
| |
Collapse
|
2
|
Luong HQ, Le TN, Lee PH, Hsieh PC. Optimization of nonspecific protease activity fabrication by Bacillus subtilis N30 isolated from Taiwan using different models of response surface methodology. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2023. [DOI: 10.1016/j.bcab.2023.102686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
|
3
|
The impact of key fermentation parameters on the production of the all-trans isomer of menaquinone-7. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
4
|
Lal N, Seifan M, Berenjian A. Optimisation of the fermentation media to enhance the production of the bioactive isomer of vitamin menaquinone-7. Bioprocess Biosyst Eng 2022; 45:1371-1390. [PMID: 35864383 PMCID: PMC9302956 DOI: 10.1007/s00449-022-02752-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/22/2022] [Indexed: 11/30/2022]
Abstract
Menaquinone-7 (MK-7) offers significant health benefits; however, only the all-trans form is biologically active. MK-7 produced through fermentation can occur as all-trans and cis isomers, and the therapeutic value of the resulting MK-7 is exclusively determined by the quantity of the all-trans isomer. Therefore, this study aimed to investigate the effect of the media composition on the isomer profile obtained from fermentation and determine the optimum media combination to increase the concentration of the all-trans isomer and diminish the production of cis MK-7. For this purpose, design of experiments (DOE) was used to screen the most effective nutrients, and a central composite face-centred design (CCF) was employed to optimise the media components. The optimum media consisted of 1% (w/v) glucose, 2% (w/v) yeast extract, 2% (w/v) soy peptone, 2% (w/v) tryptone, and 0.1% (w/v) CaCl2. This composition resulted in an average all-trans and cis isomer concentration of 36.366 mg/L and 1.225 mg/L, respectively. In addition, the optimised media enabled an all-trans isomer concentration 12.2-fold greater and a cis isomer concentration 2.9-fold less than the unoptimised media. This study was the first to consider the development of an optimised fermentation media to enhance the production of the bioactive isomer of MK-7 and minimise the concentration of the inactive isomer. Furthermore, this media is commercially promising, as it will improve the process productivity and reduce the costs associated with the industrial fermentation of the vitamin.
Collapse
Affiliation(s)
- Neha Lal
- School of Engineering, The University of Waikato, Hamilton, 3240, New Zealand
| | - Mostafa Seifan
- School of Engineering, The University of Waikato, Hamilton, 3240, New Zealand
| | - Aydin Berenjian
- School of Engineering, The University of Waikato, Hamilton, 3240, New Zealand.
- Department of Agricultural and Biological Engineering, Pennsylvania State University, 221 Agricultural Engineering Building, University Park, PA, 16802, USA.
| |
Collapse
|
5
|
Production of Vitamin K by Wild-Type and Engineered Microorganisms. Microorganisms 2022; 10:microorganisms10030554. [PMID: 35336129 PMCID: PMC8954062 DOI: 10.3390/microorganisms10030554] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/23/2022] [Accepted: 03/01/2022] [Indexed: 12/14/2022] Open
Abstract
Vitamin K is a fat-soluble vitamin that mainly exists as phylloquinone or menaquinone in nature. Vitamin K plays an important role in blood clotting and bone health in humans. For use as a nutraceutical, vitamin K is produced by natural extraction, chemical synthesis, and microbial fermentation. Natural extraction and chemical synthesis methods for vitamin K production have limitations, such as low yield of products and environmental concerns. Microbial fermentation is a more sustainable process for industrial production of natural vitamin K than two other methods. Recent advanced genetic technology facilitates industrial production of vitamin K by increasing the yield and productivity of microbial host strains. This review covers (i) general information about vitamin K and microbial host, (ii) current titers of vitamin K produced by wild-type microorganisms, and (iii) vitamin K production by engineered microorganisms, including the details of strain engineering strategies. Finally, current limitations and future directions for microbial production of vitamin K are also discussed.
Collapse
|
6
|
Naveed M, Tianying H, Wang F, Yin X, Chan MWH, Ullah A, Xu B, Aslam S, Ali N, Abbas Q, Hussain I, Khan A, Khan AM. Isolation of lysozyme producing Bacillus subtilis Strains, identification of the new strain Bacillus subtilis BSN314 with the highest enzyme production capacity and optimization of culture conditions for maximum lysozyme production. CURRENT RESEARCH IN BIOTECHNOLOGY 2022. [DOI: 10.1016/j.crbiot.2022.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
|
7
|
Park SA, Bhatia SK, Park HA, Kim SY, Sudheer PDVN, Yang YH, Choi KY. Bacillus subtilis as a robust host for biochemical production utilizing biomass. Crit Rev Biotechnol 2021; 41:827-848. [PMID: 33622141 DOI: 10.1080/07388551.2021.1888069] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Bacillus subtilis is regarded as a suitable host for biochemical production owing to its excellent growth and bioresource utilization characteristics. In addition, the distinct endogenous metabolic pathways and the suitability of the heterologous pathways have made B. subtilis a robust and promising host for producing biochemicals, such as: bioalcohols; bioorganic acids (lactic acids, α-ketoglutaric acid, and γ-aminobutyric acid); biopolymers (poly(γ-glutamic acid, polyhydroxyalkanoates (PHA), and polysaccharides and monosaccharides (N-acetylglucosamine, xylooligosaccharides, and hyaluronic acid)); and bioflocculants. Also for producing oligopeptides and functional peptides, owing to its efficient protein secretion system. Several metabolic and genetic engineering techniques, such as target gene overexpression and inactivation of bypass pathways, have led to the improvement in production titers and product selectivity. In this review article, recent progress in the utilization of robust B. subtilis-based host systems for biomass conversion and biochemical production has been highlighted, and the prospects of such host systems are suggested.
Collapse
Affiliation(s)
- Seo A Park
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea
| | - Shashi Kant Bhatia
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea.,Institute for Ubiquitous Information Technology and Application, Konkuk University, Seoul, Republic of Korea
| | - Hyun A Park
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea
| | - Seo Yeong Kim
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea
| | | | - Yung-Hun Yang
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul, Republic of Korea.,Institute for Ubiquitous Information Technology and Application, Konkuk University, Seoul, Republic of Korea
| | - Kwon-Young Choi
- Department of Environmental Engineering, College of Engineering, Ajou University, Suwon, South Korea.,Department of Environmental and Safety Engineering, College of Engineering, Ajou University, Suwon, South Korea
| |
Collapse
|
8
|
Razmjooei M, Shad E, Nejadmansouri M, Safdarianghomsheh R, Delvigne F, Khalesi M. Effect of metal support and different carbon sources on CLA production using Lactobacillus plantarum. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107715] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
9
|
Biofilm reactors for value-added products production: An in-depth review. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101662] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
10
|
Cis and trans isomers of the vitamin menaquinone-7: which one is biologically significant? Appl Microbiol Biotechnol 2020; 104:2765-2776. [PMID: 32009201 DOI: 10.1007/s00253-020-10409-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/15/2020] [Accepted: 01/23/2020] [Indexed: 12/20/2022]
Abstract
Recently, several studies have indicated that an adequate intake of menaquinone-7 (MK-7) offers numerous health benefits. However, the low availability of MK-7 in the diet necessitates the development of dietary supplements or functional food products to complement natural food sources and meet the daily intake requirements. Like most biological molecules, MK-7 can exist as geometric isomers that can occur in the cis, trans, and cis/trans forms; however, only the all-trans form is biologically significant. MK-7 is traditionally produced through bacterial fermentation, but various synthetic preparations have lately become available. The isomer composition in the final product is influenced by numerous factors, including the methods of production and purification, as well as particular environmental and storage conditions. The MK-7 profile obtained from the various production methods has not yet been elucidated, and the ideal method for the synthesis of the all-trans form of the vitamin is also debatable. Consequently, the quantification of the MK-7 profile of various products is necessary to develop an understanding of the factors that influence the proportion of isomers that are obtained in different preparations. Several possible methods exist for the quantification of MK-7 isomers, and of these, liquid chromatography in conjunction with mass spectrometry techniques appears to be the most promising. Evaluation of the isomer composition is an important consideration, as only the all-trans form sustains biological activity. Furthermore, knowledge of the prominent factors that influence the MK-7 composition may also enable their manipulation to obtain a more favorable MK-7 profile in the final product.
Collapse
|
11
|
Mahdinia E, Demirci A, Berenjian A. Evaluation of vitamin K (menaquinone-7) stability and secretion in glucose and glycerol-based media by Bacillus subtilis natto. ACTA ALIMENTARIA 2019. [DOI: 10.1556/066.2019.48.4.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- E. Mahdinia
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802. USA
| | - A. Demirci
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802. USA
| | - A. Berenjian
- Faculty of Science and Engineering, The University of Waikato, Hamilton, 3240. New Zealand
| |
Collapse
|
12
|
Improvement of menaquinone-7 production by Bacillus subtilis natto in a novel residue-free medium by increasing the redox potential. Appl Microbiol Biotechnol 2019; 103:7519-7535. [PMID: 31378837 DOI: 10.1007/s00253-019-10044-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/13/2019] [Accepted: 07/23/2019] [Indexed: 01/12/2023]
Abstract
Bacillus subtilis natto is a GRAS bacterium. Nattokinase, with fibrinolytic and antithrombotic activities, is one of the major products of this organism. It is being gradually recognized that B. subtilis natto can also be used as a biosynthetic strain for vitamin K2, which has phenomenal benefits, such as effects in the prevention of cardiovascular diseases and osteoporosis along with antitumor effects. Knocking out of the aprN gene by homologous recombination could improve the redox potential and slightly increase the concentration of MK-7. By detecting the change in redox potential during the growth of B. subtilis natto, a good oxygen supply and state of the cell membrane were found to be beneficial to vitamin K2 synthesis. A two-step RSM was used to optimize the operation parameters and substrate concentration in the new residue-free fermentation culture. The optimal conditions for the residue-free medium and control were determined. The optimum concentrations of soybean flour, corn flour, and peptone were 78.9, 72.4, and 24.8 g/L, respectively. The optimum rotational speed and volume of the culture medium using a shaking flask were 117 rpm and 10%, respectively. The state and composition of the cell membranes were more stable when engineered bacteria were cultured in this residue-free fermentation medium. Finally, the concentration of MK-7 increased by 37% to 18.9 mg/L, and the fermentation time was shortened by 24 h.
Collapse
|
13
|
Fang Z, Wang L, Zhao G, Liu H, Wei H, Wang H, Ni W, Zheng Z, Wang P. A simple and efficient preparative procedure for menaquinone-7 from Bacillus subtilis (natto) using two-stage extraction followed by microporous resins. Process Biochem 2019. [DOI: 10.1016/j.procbio.2019.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
14
|
Mahdinia E, Demirci A, Berenjian A. Biofilm reactors as a promising method for vitamin K (menaquinone-7) production. Appl Microbiol Biotechnol 2019; 103:5583-5592. [PMID: 31152205 DOI: 10.1007/s00253-019-09913-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 12/17/2022]
Abstract
Menaquinone-7 (MK-7) is the most potent subtype of vitamin K with extraordinarily high half-life in the circulatory system. Therefore, MK-7 plays a critical role in promoting human wellbeing today. Studies on MK-7 every year show more and more magnificent benefits of it in preventing cardiovascular diseases and osteoporosis to battling cancer cells, Alzheimer's and Parkinson's diseases. Thus, it needs to be supplemented to daily diet for accumulative and long-term benefits. Chemical synthesis of MK-7 produces a significant cis-isomer form of it, which has no biological activity. Fortunately, due to its key role in electron transfer in bacteria, trans-MK-7 is biosynthesized by especially Gram-positive strains mainly Bacillus genus. Concordantly, MK-7 could be produced via solid or liquid state fermentation strategies. In either regime, when static fermentation is applied in the absence of agitation and aeration, operational issues arise such as heat and mass transfer inefficiencies. Thus, scaling up the process becomes a challenge. On the other hand, studies have indicated that biofilm and pellicle formation that occur in static fermentations are key characteristics for extracellular MK-7 secretion. Therefore, this review covers the most recent discoveries of the therapeutic properties of MK-7 and optimization attempts at increasing its biosynthesis in different media compositions and effective growth parameters as well as the cutting-edge use of biofilm reactors where B. subtilis cells have the infrastructures to form mature biofilm formations on plastic composite supports. Biofilm reactors therefore can provide robust extracellular MK-7 secretion while simultaneously enduring high agitation and aeration rates, which then address the scale-up and operational issues associated with static fermentation strategies.
Collapse
Affiliation(s)
- Ehsan Mahdinia
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, State College, PA, USA
| | - Ali Demirci
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, State College, PA, USA. .,The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Aydin Berenjian
- Faculty of Science and Engineering, The University of Waikato, Hamilton, 3240, New Zealand
| |
Collapse
|
15
|
Modeling of vitamin K (Menaquinoe-7) fermentation by Bacillus subtilis natto in biofilm reactors. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2019. [DOI: 10.1016/j.bcab.2018.11.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
16
|
Mahdinia E, Demirci A, Berenjian A. Effects of medium components in a glycerol-based medium on vitamin K (menaquinone-7) production by Bacillus subtilis natto in biofilm reactors. Bioprocess Biosyst Eng 2018; 42:223-232. [PMID: 30368608 DOI: 10.1007/s00449-018-2027-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 10/17/2018] [Indexed: 12/29/2022]
Abstract
Menaquinone-7 (MK-7) as the most important form of Vitamin K has been reported to have miraculous benefits such as preventing cardiovascular diseases and osteoporosis along with antitumor effects. Therefore, there have been numerous studies in the past decades to improve MK-7 production via microbial fermentation. Unfortunately, both solid and liquid state fermentation strategies that are utilized for MK-7 production, face fundamental operational and scale-up issues as well as intense heat and mass transfer problems during fermentation. In this regard, biofilm reactors seem to be a practical solution to overcome these issues and enhance the production in agitated liquid fermentation. Therefore, this study was undertaken to utilize biofilm reactors in investigating and optimizing different media components in a glycerol-based medium. Using response surface methodology, the effects of glycerol, yeast extract, and soytone were studied in the fermentation medium on MK-7 production in biofilm reactor. With a composition of 48.2 g/L of glycerol, 8.1 g/L of yeast extracts, 13.6 g/L of soytone and 0.06 g/L of K2HPO4, MK-7 concentrations could reach 14.7 ± 1.4 mg/L in biofilm reactors, which was 57% higher compared to the MK-7 concentration achieved in suspended-cell reactors under similar conditions, while glycerol was depleted by the end of the fifth day in biofilm reactors, but glycerol was never depleted in suspended-cell reactors. Evidently, biofilm reactors present a reliable strategy to address the operational issues that occur during MK-7 biosynthesis on an industrial scale production.
Collapse
Affiliation(s)
- Ehsan Mahdinia
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ali Demirci
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Aydin Berenjian
- Faculty of Science and Engineering, The University of Waikato, Hamilton, 3240, New Zealand
| |
Collapse
|
17
|
Mahdinia E, Demirci A, Berenjian A. Implementation of fed-batch strategies for vitamin K (menaquinone-7) production by Bacillus subtilis natto in biofilm reactors. Appl Microbiol Biotechnol 2018; 102:9147-9157. [PMID: 30218375 DOI: 10.1007/s00253-018-9340-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/06/2018] [Accepted: 08/18/2018] [Indexed: 01/07/2023]
Abstract
Recent studies show the essential health benefits associated with vitamin K, especially menaquinone-7 (MK-7). These benefits include reducing risks of cardiovascular diseases, osteoporosis, and even cancer. However, MK-7 production on an industrial level is only possible through bacterial fermentation and also current static fermentation strategies are not potent enough with difficulties to scale up. Biofilm reactors, however, may be a practical alternative. Biofilm reactors provide a controlled environment for the microorganisms to form mature and robust biofilms that enable them to produce value-added products with enhanced efficiencies. In this study, fed-batch addition of glucose and glycerol were investigated to the base media in biofilm reactors, as carbon source addition seemed crucial in batch fermentations. Results indicated that fed-batch strategies can be significantly effective in glucose-based medium, increasing the end-product concentrations to 28.7 ± 0.3 mg/L of MK-7 which was 2.3 fold higher than the level produced in suspended-cell bioreactors and renders the biofilm reactors as a potential replacement for static fermentation strategies. Moreover, morphological changes of B. subtilis were tracked during the 12-day long fermentation runs and finally, SEM investigations confirmed significant biofilm and extracellular matrices formed on the plastic composite support (PCS) in the biofilm reactors. In conclusion, biofilm reactors especially with fed-batch fermentation regimes seem to be an effective tool for MK-7 production at industrial scales.
Collapse
Affiliation(s)
- Ehsan Mahdinia
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ali Demirci
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Aydin Berenjian
- Faculty of Science and Engineering, The University of Waikato, Hamilton, 3240, New Zealand
| |
Collapse
|