Plastic Composite Support Research Articles

Sustainable menaquinone-7 production through continuous fermentation in biofilm bioreactors.

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 0.12mg/L/h to 0.33mg/L/h with a dilution rate increment from 0.007 to 0.042h-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 0.084h-1 led to reduced productivity at approximately 0.16mg/L/h, likely due to insufficient retention time for effective biofilm formation. Consequently, a dilution rate of 0.042h-1 exhibited the highest productivity of 0.33mg/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 0.084h-1 dilution rate, corresponding to a 48h 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.

Enhanced exopolysaccharide production of Cordyceps militaris via mycelial cell immobilization on plastic composite support in repeated-batch fermentation

Repeated-batch fermentation with fungal mycelia immobilized in plastic composite support (PCS) eliminates the lag phase during fermentation and improves metabolite productivity. The strategy is implemented herein, and a novel modified PCS is developed to enhance exopolysaccharide (EPS) production from the medicinal fungus Cordyceps militaris. A modified PCS (SYE + PCS) was made by compositing polypropylene (PP) with a nutrient mixture containing soybean hull, peptone, yeast extract, and minerals (SYE+). The use of SYE + PCS has consistent cell productivity throughout the multiple fermentation cycles, which resulted in a more higher cell productivity after second batch compared to unmodified PCS. The cell grown on SYE + PCS also generates a higher yield of EPS (3.36, 6.93, and 5.72 g/L in the first, second, and third fermentation cycles, respectively) up to three-fold higher than the cell immobilized on unmodified PCS. It is also worth noting that the EPS from mycelium grown on SYE + PCS contains up to 2.3-fold higher cordycepin than those on unmodified PCS. The presence of nutrients in SYE + PCS also affects the hydrophobicity and surface roughness of the PC, improving mycelial cell adhesion. This study also provides a preliminary antioxidant activity assessment of EPS from immobilized C. militaris grown with SYE + PCS.

Biofilm reactors as a promising method for vitamin K (menaquinone-7) production.

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.

Implementation of fed-batch strategies for vitamin K (menaquinone-7) production by Bacillus subtilis natto in biofilm reactors.

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 ± 0.3mg/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.

Utilization of glucose-based medium and optimization of Bacillus subtilis natto growth parameters for vitamin K (menaquinone-7) production in biofilm reactors

Abstract Menaquinone-7 (MK-7) is the most potent form of vitamin K prescribed as a dietary supplement. MK-7 is commonly produced via static fermentation of Bacillus subtilis natto. The fermentation of this bacterium is associated with formation of large amounts of pellicles and biofilm, which are effective in MK-7 production, but also result in significant heat and mass transfer challenges during the scale-up process. Thus, the objectives of this study were to develop and evaluate the possibility of using a biofilm reactor for MK-7 production. In this research, biofilm reactors were constructed using the Plastic Composite Supports (PCS). In order to optimize the fermentation parameters for MK-7 production, Central Composite Design (CCD) was carried out along with supplementary runs to determine the optimum temperature, pH, and agitation. The biofilm reactors were able to produce a maximum concentration of 18.45 ± 0.76 mg/L of MK-7, which was 237% higher than the suspended-cell fermentation. Therefore, the present work suggests the possibility of using biofilm reactors as a new and effective fermentation strategy to address the issues associated with MK-7 fermentation.

Optimization of Bacillus subtilis natto growth parameters in glycerol-based medium for vitamin K (Menaquinone-7) production in biofilm reactors.

Menaquinone-7 (MK-7) is the key form of vitamin K used as a dietary supplement and its production revolves around Bacillus subtilis natto. Current fermentation strategies, which suggest static fermentations without aeration and agitation, can be problematic for large scale MK-7 production due to biofilm formation. The use of biofilm reactors, therefore, is proposed in the present study, which could utilize both agitation and aeration without interrupting MK-7 secretion. In this study, biofilm reactors were constructed using the selected plastic composite support (PCS) and B. subtilis natto strain for MK-7 production. Using response surface methodology (RSM), optimum growth parameters including temperature, pH, and agitation were determined in a glycerol-based medium. Results were presented in a statistical model (R 2 = 0.90), leading to optimum growth conditions of temperature (35°C), agitation (200rpm) and pH (6.58). Model-predicted MK-7 concentration was validated and MK-7 concentration of 12.09mg/L was produced in the biofilm reactor. The obtained concentration was 58% higher as compared to the suspended-cell culture (7.67mg/L). The results of this study will provide a critical step towards improved industrial scale production of MK-7.

Strain and plastic composite support (PCS) selection for vitamin K (Menaquinone-7) production in biofilm reactors.

Menaquinone-7 (MK-7), a subtype of vitamin K, has received a significant attention due to its effect on improving bone and cardiovascular health. Current fermentation strategies, which involve static fermentation without aeration or agitation, are associated with low productivity and scale-up issues and hardly justify the commercial production needs of this vitamin. Previous studies indicate that static fermentation is associated with pellicle and biofilm formations, which are critical for MK-7 secretion while posing significant operational issues. Therefore, the present study is undertaken to evaluate the possibility of using a biofilm reactor as a new strategy for MK-7 fermentation. Bacillus species, namely, Bacillus subtilis natto, Bacillus licheniformis, and Bacillus amyloliquifaciens as well as plastic composite, supports (PCS) were investigated in terms of MK-7 production and biofilm formation. Results show the possibility of using a biofilm reactor for MK-7 biosynthesis. Bacillus subtilis natto and soybean flour yeast extract PCS in glucose medium were found as the most potent combination for production of MK-7 as high as 35.5mg/L, which includes both intracellular and extracellular MK-7.

Simultaneous saccharification and fermentation of ethanol from potato waste by co-cultures of Aspergillus niger and Saccharomyces cerevisiae in biofilm reactors

Novel approaches for bioethanol production from industrial wastes have gained attention due to not only maximize the ethanol production productivity, but also reduce the production cost. Part of the production cost includes cost of the enzymes needed for saccharification step during the starch hydrolyzation, which can be significant cost depending on the enzymes’ performances. Therefore, in this study, simultaneous saccharification and fermentation (SSF) of ethanol by co-cultures of Aspergillus niger and Saccharomyces cerevisiae was assessed in a potato waste based medium by using biofilm reactors. The plastic composite supports (PCS) were studied for biofilm formation. Effects of temperature, pH, and aeration rates in biofilm reactors were evaluated by response surface methodology and the optimal conditions were found to be 35°C, pH 5.8, and no aeration. The maximum ethanol concentration of 37.93g/L was achieved at the end of 72h fermentation, with a 0.41g ethanol/g starch yield. Finally, biofilm formation of co-culture on PCS was also evaluated by scanning electron microscope. In conclusion, the results demonstrated that PCS can be utilized for SSF processes for ethanol production in biofilm reactors with co-cultures by using starchy industrial wastes.

Ethanol production in biofilm reactors from potato waste hydrolysate and optimization of growth parameters for Saccharomyces cerevisiae

Bioethanol production is of great interest to meet the renewable energy demand and reduce the negative environmental impacts of petroleum fuel while providing energy security for countries. In order to make ethanol production cost-competitive, inexpensive and easily available feedstocks are needed as well as novel processing technologies with higher productivities. In this study, biofilm reactors have been utilized as a novel approach for production of bioethanol from potato waste hydrolysate by optimizing the growth parameters for Saccharomyces cerevisiae in repeated-batch biofilm reactor. First of all, in order to achieve a successful biofilm formation, plastic composite supports (PCS) evaluated and the PCS composed of polypropylene, soybean hull, soybean flour, yeast extract, and salts was selected for ethanol fermentation with S. cerevisiae. Then Box–Behnken design of response surface method (RSM) was employed to optimize the growth parameters, pH, temperature, and agitation. Optimum conditions for ethanol fermentation was found to be pH 4.2, temperature 34°C, and 100rpm resulting 37.05g/L ethanol with a 2.31g/L/h productivity and 92.08% theoretical yield. The results indicated that biofilm reactors with PCS can enhance the ethanol fermentation from industrial potato wastes.

Enrichment of two isoflavone aglycones in black soymilk by Rhizopus oligosporus NTU 5 in a plastic composite support bioreactor.

A plastic composite support (PCS) bioreactor was implemented to evaluate the effects on isoflavone deglycosylation in black soymilk fermented by Rhizopus oligosporus NTU 5. Evaluation for the optimal PCS for mycelia immobilisation was conducted, which led to the significant results that the most mycelium weight (0.237 g per PCS, P < 0.05) is held by an S-type PCS; therefore, it was selected for black soymilk fermentation. It was found that the PCS fermentation system without pH control exhibits better efficiency of isoflavone bioconversion (daidzin to daidzein, and genistin to genistein) than the one with pH control at pH 6.5. As for the long-run fermentation, those without pH control indeed accelerate the isoflavone bioconversion by continuously releasing β-glucosidase into soymilk. Deglycosylation can be completed in 8 to 24 h and sustained for at least 34 days as 26 batches. The non-pH-control fermentation system also exhibits the highest total phenolic content (ranged from 0.147 to 0.340 mg GAE mL(-1) sample) when compared to the pH-controlled and suspended ones. Meanwhile, the black soymilk from the 22nd batch with 8 h fermentation demonstrated the highest DPPH radical scavenging effect (54.7%). A repeated-batch PCS fermentation system was established to accelerate the deglycosylation rate of isoflavone in black soymilk. © 2015 Society of Chemical Industry.

Evaluation of kojic acid production in a repeated-batch PCS biofilm reactor

In this study, kojic acid, a secondary metabolite as an industrially important compound, was produced by Aspergillus oryzae (A. oryzae), which was immobilized in plastic composite support (PCS) bioreactor. Nitrogen deficient medium was applied to increase the production of KA in PCS-immobilized bioreactor. The efficiency of immobilized culture for kojic acid (KA) production and the effect of morphology of A. oryzae on KA production were evaluated. After three cycles of cultivation, 83.47g/L of KA was produced in PCS bioreactor in nitrogen deficient medium with productivity of 3.09g/L/d, which is higher than free suspension culture in batch fermentation. The morphology of A. oryzae mycelium changed under nitrogen starvation. Feather-like mycelium was observed with increasing KA production. RNA expression (kojA and kojT) results indicated that the nitrogen deficient environment had strong influence on KA production on the transcriptional level. PCS immobilized fermentation system, which allowed a repeated-batch fermentation with higher production and productivity, is a potential tool in industrial production of KA.

Enhanced human lysozyme production by Kluyveromyces lactis K7 in biofilm reactor coupled with online recovery system

Kluyveromyces lactis K7 is a genetically modified microorganism, which is proposed to produce the human lysozyme commercially. Up to now, human lysozyme production with this strain was improved by the application of biofilm reactor with plastic composite supports compared to the suspended-cell bioreactor. The goal of this study was to further enhance the human lysozyme production with a simultaneous fermentation in biofilm reactor and online recovery system. For the adsorption of human lysozyme, various percent ratios (wt/v) of silicic acid: fermentation broth as the absorbent, temperature, and pH of the fermentation broth were evaluated, whereas temperature, pH, sodium dodecyl sulfate, NaCl, and ethanol concentrations in the eluent were evaluated for the desorption of the human lysozyme from absorbent. The results demonstrated that the best adsorption (95.6% adsorption) was obtained at 25°C, pH 4, and 25% silicic acid: fermentation broth volume ratio and the best desorption parameters were determined as 25°C, pH 6.2, and 5% (wt/v) sodium dodecyl sulfate with 1M NaCl and 20% (v/v) ethanol as eluent among tested variables. Four repetitive desorption process yielded up to 98% desorption. Finally, the simultaneous fermentation and online recovery system improved the production of human lysozyme to 280.4U/mL, which is a 63% improvement compared to the biofilm bioreactor without the online recovery system. Therefore, this approach is not only enhanced the human lysozyme production, but also allowed the recovery process simultaneously with fermentation.

Enhanced human lysozyme production in biofilm reactor by Kluyveromyces lactis K7

Lysozyme is an antimicrobial compound, which has been used in pharmaceutical and food industries. Chicken egg is the commercial source of lysozyme. However, human lysozyme is more effective and safer than egg-white lysozyme. Human milk is an important source for human lysozyme, but it is not feasible to provide the needed lysozyme commercially. Biofilm reactors provide passive immobilization of cells onto the solid support, which may lead to higher productivity. The aim was to evaluate the fermentation medium composition for enhanced human lysozyme production by Kluyveromyces lactis K7 in biofilm reactor with plastic composite supports. Yeast nitrogen base was selected as the best nitrogen source when compared to the yeast extract and corn steep liquor. Moreover, inhibition effect of NaCl and NH4Cl at the concentrations of 25 and 50mM was observed. Three factors Box–Behnken response surface design was conducted and the results suggested 16.3% lactose, 1.2% casamino acid, 0.8% yeast nitrogen base as optimum medium composition for maximum human lysozyme production. Overall, the human lysozyme production by K. lactis K7 was increased to 173U/ml, which is about 23% improvement in biofilm reactor and 57% improvement compared to the suspended-cell fermentation.

Semi-continuous bacterial cellulose production in a rotating disk bioreactor and its materials properties analysis

A rotating disk bioreactor with plastic composite support (PCS) as the solid support was evaluated for bacterial cellulose (BCel) production. Results demonstrated that BCel can be produced in a semi-continuous manner. The BCel productivity reached around 0.24 g/L/day and can be sustained for at least five consecutive runs. Scanning electron microscopy results confirmed that Gluconacetobacter can attach on the PCS surface, which eliminates the need of reinoculation. X-ray diffraction patterns and mechanical analysis of BCel produced from this semi-continuous process exhibited lower crystallinity (66.9 %) and mechanical property (Young's modulus of 372.5 MPa) when compared with the BCel obtained from static culture (crystallinity = 88.7 %, Young's modulus of 3,955.6 MPa). Both BCel samples possessed similar water content (98.66 vs. 99.04 %) and thermostability (around 346 °C). In conclusion, the PCS rotating disk bioreactor system can be used to produce BCel in pellicle form with enhanced productivity and, meanwhile, can be scaled up easily to meet commercial need.

Production of human lysozyme in biofilm reactor and optimization of growth parameters of Kluyveromyces lactis K7

Lysozyme (1,4-β-N-acetylmuramidase) is a lytic enzyme, which degrades the bacterial cell wall. Lysozyme has been of interest in medicine, cosmetics, and food industries because of its anti-bactericidal effect. Kluyveromyces lactis K7 is a genetically modified organism that expresses human lysozyme. There is a need to improve the human lysozyme production by K. lactis K7 to make the human lysozyme more affordable. Biofilm reactor provides high biomass by including a solid support, which microorganisms grow around and within. Therefore, the aim of this study was to produce the human lysozyme in biofilm reactor and optimize the growth conditions of K. lactis K7 for the human lysozyme production in biofilm reactor with plastic composite support (PCS). The PCS, which includes polypropylene, soybean hull, soybean flour, bovine albumin, and salts, was selected based on biofilm formation on PCS (CFU/g), human lysozyme production (U/ml), and absorption of lysozyme inside the support. To find the optimum combination of growth parameters, a three-factor Box-Behnken design of response surface method was used. The results suggested that the optimum conditions for biomass and lysozyme productions were different (27°C, pH 6, 1.33vvm for biomass production; 25°C, pH 4, no aeration for lysozyme production). Then, different pH and aeration shift strategies were tested to increase the biomass at the first step and then secrete the lysozyme after the shift. As a result, the lysozyme production amount (141U/ml) at 25°C without pH and aeration control was significantly higher than the lysozyme amount at evaluated pH and aeration shift conditions (p < 0.05).

Thermo-aerobic bacteria from geothermal springs in Saudi Arabia

Biodiversity in geothermal springs in Saudi Arabia appears scanty and has not been thoroughly investigated. Geothermal springs are scattered in several areas in Saudi Arabia. Water samples were collected from ten hot springs and analyzed for different physical and chemical parameters. Fifteen isolates of thermo-aerobic bacteria were found. Bacillus cereus, B. licheniformis, B. thermoamylovorans, Pseudomonas sp., Pseudomonas aeruginosa and Enterobacter sp. were dominant in hot springs. Genetic relatedness indicated that eleven Bacillus spp. grouped together formed several clusters within one main group with high similarity. Plastic composite support tubes (PCS) were employed to stimulate the bacterial growth at high temperatures. The optimum temperature of isolates was 60°C. Thus, different blend of PCS were used to enhance the growth at higher temperatures. PCS blended with 20 and 15% (w/w) of dates pits and 5% (w/w) of yeast extract stimulated the growth of B. thermoamylovorans at 90°C.

Continuous pullulan fermentation in a biofilm reactor

Biofilm is a natural form of cell immobilization in which microorganisms attach onto solid support. In this study, a pigment-reduced pullulan-producing strain, Aureobasidium pullulans (ATCC 201253), was used for continuous pullulan fermentation in a plastic composite support (PCS) biofilm reactor. Optimal conditions for the continuous pullulan production were determined by evaluating the effects of the feeding medium with various concentrations of ammonium sulfate and sucrose and dilution rate. Pullulan concentration and production rate reached maximum (8.3 g/l and 1.33 g/l/h) when 15 g/l of sucrose, 0.9 g/l of ammonium sulfate, and 0.4 g/l of yeast extract were applied in the medium, and the dilution rate was at 0.16 h(-1). The purity of produced pullulan was 93.0%. The ratio of hyphal cells of A. pullulans increased when it was grown on the PCS shaft. Overall, the increased pullulan productivity can be achieved through biomass retention by using PCS biofilm reactor.

Enhanced pullulan production in a biofilm reactor by using response surface methodology

Pullulan is a linear homopolysaccharide that is composed of glucose units and often described as alpha-1, 6-linked maltotriose. In this study, response surface methodology using Box-Behnken design was employed to study the effects of sucrose and nitrogen concentrations on pullulan production. A total of 15 experimental runs were carried out in a plastic composite support biofilm reactor. Three-dimensional response surface was generated to evaluate the effects of the factors and to obtain the optimum condition of each factor for maximum pullulan production. After 7-day fermentation with optimum condition, the pullulan production reached 60.7 g/l, which was 1.8 times higher than the result from initial medium, and was the highest yield reported to date. The quality analysis demonstrated that the purity of produced pullulan was 95.2%, and its viscosity was 2.5 centipoise (cP), which is higher than the commercial pullulan and related to its molecular weight. Fourier transform infrared spectroscopy (FTIR) also suggested that the produced exopolysaccharide was pullulan.

Effects of plastic composite support and pH profiles on pullulan production in a biofilm reactor

Pullulan is a linear homopolysaccharide which is composed of glucose units and often described as alpha-1, 6-linked maltotriose. The applications of pullulan range from usage as blood plasma substitutes to environmental pollution control agents. In this study, a biofilm reactor with plastic composite support (PCS) was evaluated for pullulan production using Aureobasidium pullulans. In test tube fermentations, PCS with soybean hulls, defatted soy bean flour, yeast extract, dried bovine red blood cells, and mineral salts was selected for biofilm reactor fermentation (due to its high nitrogen content, moderate nitrogen leaching rate, and high biomass attachment). Three pH profiles were later applied to evaluate their effects on pullulan production in a PCS biofilm reactor. The results demonstrated that when a constant pH at 5.0 was applied, the time course of pullulan production was advanced and the concentration of pullulan reached 32.9 g/L after 7-day cultivation, which is 1.8-fold higher than its respective suspension culture. The quality analysis demonstrated that the purity of produced pullulan was 95.8% and its viscosity was 2.4 centipoise. Fourier transform infrared spectroscopy spectra also supported the supposition that the produced exopolysaccharide was mostly pullulan. Overall, this study demonstrated that a biofilm reactor can be successfully implemented to enhance pullulan production and maintain its high purity.

Enhanced production of bacterial cellulose by using a biofilm reactor and its material property analysis

Bacterial cellulose has been used in the food industry for applications such as low-calorie desserts, salads, and fabricated foods. It has also been used in the paper manufacturing industry to enhance paper strength, the electronics industry in acoustic diaphragms for audio speakers, the pharmaceutical industry as filtration membranes, and in the medical field as wound dressing and artificial skin material. In this study, different types of plastic composite support (PCS) were implemented separately within a fermentation medium in order to enhance bacterial cellulose (BC) production by Acetobacter xylinum. The optimal composition of nutritious compounds in PCS was chosen based on the amount of BC produced. The selected PCS was implemented within a bioreactor to examine the effects on BC production in a batch fermentation. The produced BC was analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA). Among thirteen types of PCS, the type SFYR+ was selected as solid support for BC production by A. xylinum in a batch biofilm reactor due to its high nitrogen content, moderate nitrogen leaching rate, and sufficient biomass attached on PCS. The PCS biofilm reactor yielded BC production (7.05 g/L) that was 2.5-fold greater than the control (2.82 g/L). The XRD results indicated that the PCS-grown BC exhibited higher crystallinity (93%) and similar crystal size (5.2 nm) to the control. FESEM results showed the attachment of A. xylinum on PCS, producing an interweaving BC product. TGA results demonstrated that PCS-grown BC had about 95% water retention ability, which was lower than BC produced within suspended-cell reactor. PCS-grown BC also exhibited higher Tmax compared to the control. Finally, DMA results showed that BC from the PCS biofilm reactor increased its mechanical property values, i.e., stress at break and Young's modulus when compared to the control BC. The results clearly demonstrated that implementation of PCS within agitated fermentation enhanced BC production and improved its mechanical properties and thermal stability.