Efektivitas Larva Black Soldier Fly (Hermetia Iilucens) dalam Mereduksi Sampah Organik

The composition of waste in Indonesia is dominated by organic waste. The waste processing process must be improved to prevent pollution in the market environment. The bioconversion process using Black Soldier Fly larvae or maggots is an effective way to process organic waste. The aim of this study was to determine the effect of feeding on the initial maggot biomass to the addition of the final maggot biomass, determine the maximum maggot weight and determine substrate consumption. This quantitative research used a completely randomized design method consist of five treatments and four replications. The various feeding between total feed and larva were A treatment (270 gram: 150 gram), B (210 gram : 150 gram), C (150 gram : 150 gram), D ( 90 gram : 150 gram) and E ( 30 gram : 150 gras). The data analysis technique used variance test and Duncan’s mean difference test. The result showed that the addition of coconut pulp feed affects to the final weight of the maggot and the value of substrate consumption. The addition of coconut dregs feed which maximally affects to the final weight of the maggot showed in A treatment which ratio coconut dregs: larva (270 gram : 150 gram). The A treatment gave an average final weight of maggot 195 grams in 18 days. The maximum reduction of coconut dregs in the bioconversion process was observed in treatment E with a substrate consumption value of 55%.

Kinetic Modelling of Oxalic Acid Production from Cassava Whey by Aspergillus niger

The transition from eco-harmful chemical processes to bio-based production of organics has been challenged by the complex nature of fermentation processes. The growth kinetics and modelling of oxalic acid production from cassava whey by Aspergillus niger (MW188538) was studied in a batch fermentation system. The production kinetics of the fermentation study was fitted into the Monod, Leudeking-Piret and Andrews kinetic models. The oxalic acid, reducing sugar, cell dry weights were determined according to the experimental design. The results showed that the production of oxalic acid was associated with A. niger with significant R2 value of 0.96 and growth rate of 0.065 biomass/day using the cassava whey as a sole carbon source. The substrate consumption rate of 14.28 and 11.16 mg/g/day with an R2 value of 0.94 and 0.96 suggest there was a healthy utilization of the Cassava whey and yeast extract as described by the Leudeking-Piret and Monod models.

Mathematical Analysis and Update of ADM1 Model for Biomethane Production by Anaerobic Digestion

Biomethane is a renewable product that can directly substitute its fossil counterpart, although its synthesis from residual biomasses has some hurdles. Because of the complex nature of both biomasses and the microbial consortia involved, innovative approaches such as mathematical modeling can be deployed to support possible improvements. The goal of this study is two-fold, as we aimed to modify a part of the Anaerobic Digestion Model No. 1 (ADM1), describing biomethane production from activated sludge, matching with its actual microbial nature, and to use the model for identifying relevant parameters to improve biomethane production. Firstly, thermodynamic analysis was performed, highlighting the direct route from glucose to biomethane as the most favorable. Then, by using MATLAB® and Simulink Toolbox, we discovered that the model fails to predict the microbiological behavior of the system. The structure of the ADM1 model was then modified by adding substrate consumption yields in equations describing microbial growth, to better reflect the consortium behavior. The updated model was tested by modifying several parameters: the coefficient of decomposition was identified to increase biomethane production. Approaching mathematical models from a microbiological point of view can lead to further improvement of the models themselves. Furthermore, this work represents additional evidence of the importance of informatics tools, such as bioprocess simulations to foster biomethane role in bioeconomy.

Detoxification of Molasses and Production of Mycelial Mass and Valuable Metabolites by Morchella Species

Edible wild ascomycetes Morchella rotunda, M. vulgaris and M. conica were cultivated in liquid static and agitated flasks of sucrose and molasses substrates with a C/N ratio of 20 and 25. The impact of four substrates on the production and quality characteristics of morels was examined. Evaluation included determination of the dry mycelial mass, intra-cellular (IPS) and extra-cellular (EPS) polysaccharides, total phenolic (TPC) and antioxidant (TAC) components, proteins, as well as the degree of phenolic content reduction and decolorization of molasses. The influence of agitation conditions was also evaluated. Results showed that substrate consumption, biomass formation and secondary metabolites production were substrate, species, and C/N ratio dependent. Among species, M. conica achieved the maximum biomass (18.16 g/L) and IPS (4.8 g/L) production and significant phenolic reduction (56.6%) and decolorization (26.7%). The maximum EPS (3.94 g/L) was noted by M. rotunda, whereas TPC (32.2 mg/g), TAC (6.0 mg/g) and cellular protein (7.6% w/w) were produced in sufficient amounts. These results strongly support the use of Morchella mushrooms as a biological detoxification agent of molasses in liquid fermentations and indicate their nutritional and medicinal value.

Biotransformation of congo red in a UASB reactor under salinity conditions using immobilized redox mediator in granular activated carbon

Azo dyes are susceptible to be treated by reductive biotransformation process under anaerobic conditions. The process can be accelerated by the addition of quinones and humic substances acting as redox mediators (RM). In this study, the anthraquinone-2-sulfonate (AQS) was immobilized on granular activated carbon (GAC) to evaluate the reductive biotransformation of congo red (CR) in an up-flow anaerobic sludge blanket reactor (UASB). The syudy was divided in five stages, where the reactors with immobilized RM and without RM were operated under different salinity levels (1% and 3%) and hydraulic retention times (HRT = 5 and 10 h). The reactor with immobilized RM (GAC-AQS) achieved a decolorization efficiency of 96.1% and substrate consumption of 98.8% with a HRT = 15 h and 1% of salinity. Nonetheless, with a salinity of 3% and the same HRT, the efficiency was similar (95.6%). The reactor provided with unmodified GAC achieved values below those observed in the reactor GAC-AQS, with decolorization efficiencies of 90.8% and 75.8%, and substrate consumption of 97.1% and 88.4%, for the stages IV and V, respectively. The microbial consortium sued was able to promote the biotransformation of azo dye and no inhibitory effects were identified.

Peculiar Response in the Co-Culture Fermentation of Leuconostoc mesenteroides and Lactobacillus plantarum for the Production of ABE Solvents

Two bacterial strains (CL11A and CL11D) that are capable of ABE fermentation, identified as Leuconostoc mesenteroides and Weissella cibari, were isolated from the soil surrounding the roots of bean plants. Another strain (ZM 3A), identified as Lactobacillus plantarum, which is capable of purely ethanolic fermentation was isolated from sugarcane. Glucose was used as a standard substrate to investigate the performance of these strains in mono—and co-culture fermentation for ABE production. The performance parameters employed in this study were substrate degradation rates, product and metabolite yields, pH changes and microbial growth rates. Both ABE isolates were capable of producing the three solvents but Leuconostoc mesenteroides had a higher specificity for ethanol than Weissella cibari. The co-culturing of Leuconostoc mesenteroides and Lactobacillus plantarum enhanced ethanol production at the expense of both acetone and butanol, and also influenced the final substrate consumption rate and product yield. The experiments indicated the potential of these niche environments for the isolation of ABE-producing microorganisms. This study contributes to the formulation of ideal microbial co-culture and consortia fermentation, which seeks to maximize the yield and production rates of favored products.

A novel strain of Stenotrophomonas acidaminiphila produces super-active alkaline protease during cassava effluent fermentation: process optimization, kinetic modeling and scale-up

Microbial fermentations for value-added metabolites production are exploited for efficient bioconversion of agro-industrial wastes for the dual purposes of pollution abatement and cost-effectiveness. In the present study, the regular 2-level factorial design was employed to screen fermentation parameters that enhance production of a novel alkaline protease by a strain of Stenotrophomonas acidaminiphila using cassava processing effluent as substrate. Data from randomized experiments of central composite rotatable design for improved enzyme activity, guided by path of steepest ascent experiments, were modeled and optimized by response surface methodology (RSM). Shake flask kinetics of production under optimized conditions was modeled by logistic and modified Gompertz models and determinations of maximum specific growth rate, µmax, maximum volumetric rate of substrate consumption, rsm, maximum volumetric rate of biomass formation, rxm and specific yield of product, Yp/x were made. Logistic model poorly fitted RSM-generated product formation and substrate consumption data. However, biomass formation was accurately fitted (adjusted r2 >99%), with µmax of 0.471 h-1. The modified Gompertz model, on the contrary, more accurately fitted all three major response data with minimal mean squared error. Potential for scale-up of bioprocess evaluated in 5-L bioreactor satisfactorily revealed 8.5-fold more substrate consumption in bioreactor than in shake flask. The 86.76-fold aqueous two-phase system-purified protease had a specific activity of 1416.73 Umg-1 which improved with increasing surfactant concentration. These results suggest significant bioprocess potential for sustainable cassava effluent management and concomitant commercial production of alkaline protease for industrial detergent application.

A Novel Strain of Stenotrophomonas Acidaminiphila Produces Super-active Alkaline Protease During Cassava Effluent Fermentation: Process Optimization, Kinetic Modeling and Scale-up

PurposeMicrobial fermentations for value-added metabolites production are exploited for efficient bioconversion of agro-industrial wastes for the dual purposes of pollution abatement and cost-effectiveness.MethodsIn the present study, the regular 2-level factorial design was employed to screen fermentation parameters that enhance production of a novel alkaline protease by a strain of Stenotrophomonas acidaminiphila using cassava processing effluent as substrate. Data from randomized experiments of central composite rotatable design for improved enzyme activity, guided by path of steepest ascent experiments, were modeled and optimized by response surface methodology (RSM). Shake flask kinetics of production under optimized conditions was modeled by logistic and modified Gompertz models and determinations of maximum specific growth rate, µmax, maximum volumetric rate of substrate consumption, rsm, maximum volumetric rate of biomass formation, rxm and specific yield of product, Yp/x were made.ResultsLogistic model poorly fitted RSM-generated product formation and substrate consumption data. However, biomass formation was accurately fitted (adjusted r2 >99%), with µmax of 0.471 h-1. The modified Gompertz model, on the contrary, more accurately fitted all three major response data with minimal mean squared error. Potential for scale-up of bioprocess evaluated in 5-L bioreactor satisfactorily revealed 8.5-fold more substrate consumption in bioreactor than in shake flask. The 86.76-fold aqueous two-phase system-purified protease had a specific activity of 1416.73 Umg-1 which improved with increasing surfactant concentration.ConclusionThese results suggest significant bioprocess potential for sustainable cassava effluent management and concomitant commercial production of alkaline protease for industrial detergent application.

Screening and Growth Characterization of Non-conventional Yeasts in a Hemicellulosic Hydrolysate

Lignocellulosic biomass is an attractive raw material for the sustainable production of chemicals and materials using microbial cell factories. Most of the existing bioprocesses focus on second-generation ethanol production using genetically modified Saccharomyces cerevisiae, however, this microorganism is naturally unable to consume xylose. Moreover, extensive metabolic engineering has to be carried out to achieve high production levels of industrially relevant building blocks. Hence, the use of non-Saccharomyces species, or non-conventional yeasts, bearing native metabolic routes, allows conversion of a wide range of substrates into different products, and higher tolerance to inhibitors improves the efficiency of biorefineries. In this study, nine non-conventional yeast strains were selected and screened on a diluted hemicellulosic hydrolysate from Birch. Kluyveromyces marxianus CBS 6556, Scheffersomyces stipitis CBS 5773, Lipomyces starkeyi DSM 70295, and Rhodotorula toruloides CCT 7815 were selected for further characterization, where their growth and substrate consumption patterns were analyzed under industrially relevant substrate concentrations and controlled environmental conditions in bioreactors. K. marxianus CBS 6556 performed poorly under higher hydrolysate concentrations, although this yeast was determined among the fastest-growing yeasts on diluted hydrolysate. S. stipitis CBS 5773 demonstrated a low growth and biomass production while consuming glucose, while during the xylose-phase, the specific growth and sugar co-consumption rates were among the highest of this study (0.17 h–1 and 0.37 g/gdw*h, respectively). L. starkeyi DSM 70295 and R. toruloides CCT 7815 were the fastest to consume the provided sugars at high hydrolysate conditions, finishing them within 54 and 30 h, respectively. R. toruloides CCT 7815 performed the best of all four studied strains and tested conditions, showing the highest specific growth (0.23 h–1), substrate co-consumption (0.73 ± 0.02 g/gdw*h), and xylose consumption (0.22 g/gdw*h) rates. Furthermore, R. toruloides CCT 7815 was able to produce 10.95 ± 1.37 gL–1 and 1.72 ± 0.04 mgL–1 of lipids and carotenoids, respectively, under non-optimized cultivation conditions. The study provides novel information on selecting suitable host strains for biorefinery processes, provides detailed information on substrate consumption patterns, and pinpoints to bottlenecks possible to address using metabolic engineering or adaptive evolution experiments.

Kinetics of Saccharomyces cerevisiae Fermentation under Metal Ions Stress during Ethanol Production

This research investigated the effects of inorganic compounds or metal ions (calcium ion, Ca2+; potassium ion, K+; magnesium ion, Mg2+) on ethanol production efficiency invertase, an enzyme produced by Saccharomyces cerevisiae, in sucrose solution, which was the substrate for yeast fermentation. The results showed that all metal ions (concentration 0.20 and 0.60 % (w/v)) acted as inhibitors on invertase activity in the order Ca2+ > K+ > Mg2+. Subsequently, these ions inhibited sugar conversion, reducing sucrose utilization and less glucose and fructose consumption based on the high content of remaining sugars in the culture medium. The reduction of the substrate was due to the consumption and an increased growth rate of S. cerevisiae, which all resulted in low efficiency of ethanol production and an increase in glycerol content. The glycerol content was increased due to yeast cells' developed mechanism or adaptation to enhance cell survival following metal ion contamination, especially from Ca2+ and K+; furthermore, the glycerol content significantly increased during the changed conditions, such as when the sugars were nearly all consumed. The kinetic parameters such as specific growth rate (µ-1), substrate consumption rate (Qs), and ethanol production of the research work were also undertaken. In conclusion, metal ion contamination in the sucrose substrate of yeast fermentation resulted in low efficiency of ethanol production, specific growth rate, and substrate consumption rate decrease with the Ca2+ ion (concentration 0.20 - 0.60 % (w/v)) acting more harshly as an inhibitor of ethanol production than the other ions, particularly where there was a high concentration of contamination.