Fermentation Inoculum Research Articles

A Semi-Continuous Fermentation Process for Pulque Production Using Microfiltration-Sterilized Aguamiel and Aseptic Conditions to Standardize the Overall Quality of the Beverage

Despite the current appreciation of pulque as a probiotic fermented beverage, pulque has been also regarded as a poor-quality product, particularly due to the lack of sanitary control during its elaboration. To address this problem, a semi-continuous fermentation system was established, emulating the artisanal production process. Microfiltration-sterilized aguamiel was employed as the substrate, whereas a good-quality pulque was used as the fermentation inoculum. During the fermentation, the physicochemical, microbiological (lactic acid and Leuconostoc-type bacteria and yeasts) and sensory characteristics of the must were monitored. The isolated microorganisms were identified by molecular biology and MALDI-MS techniques. The sterilization of aguamiel by microfiltration did not negatively affect its physicochemical attributes. After 6–8 days of operation of the semi-continuous bioreactor, the fermentation reached a quasi-stationary state considering most of the parameters monitored during the experiment. The final fermentation product presented similar physicochemical, microbial and sensory properties to those of the pulque inoculum. The genera identified were Leuconostoc, Lentilactobacillus, Lactobacillus, Liquorilactobacillus, Fructilactobacillus and Saccharomyces. The strains Lentilactobacillus diolivorans and Liquorilactobacillus capillatus and uvarum have not been previously isolated from pulque. In conclusion, the fermentation system developed in this work was effective to standardize the quality of pulque while preserving the positive attributes of the artisanal process, thus harnessing the probiotic properties of pulque.

Licuri Kernel (Syagrus coronata (Martius) Beccari): A Promising Matrix for the Development of Fermented Plant-Based Kefir Beverages.

New licuri-based kefir beverages were obtained using water kefir grains as fermentation inoculum (1, 2.5, and 5%) under different fermentation times (24 and 48 h). Metagenomic sequencing of the kefir grains adapted to the aqueous licuri extract revealed Lactobacillus hilgardii and Brettanomyces bruxellensis to be predominant in this inoculum. The excellent adaptation of the kefir grains to the licuri extract raised the possibility of prebiotic action of these almonds. The beverages showed acidity values between 0.33 ± 0.00 and 0.88 ± 0.00 mg lactic acid/100 mL and pH between 3.52 ± 0.01 and 4.29 ± 0.04. The viability of lactic acid bacteria in the fermented beverages was equal to or greater than 108 CFU/mL, while yeasts were between 104 and 105 CFU/mL. There were significant differences (p < 0.05) in the proximate composition of the formulations, especially in the protein (1.37 ± 0.33-2.16 ± 0.84) and carbohydrate (5.86 ± 0.19-11.51 ± 1.26) contents. In addition, all the samples showed good stability in terms of acidity, pH, and viability for LAB and yeasts during 28 days of storage (4 °C). Overall, the beverages showed a dominant yellow-green color, non-Newtonian pseudoplastic behavior, and high mean scores in the sensory evaluation. This study provided evidence of the emerging potential of licuri in the plant-based beverage industry.

In vitro fermentation of substrates from Saccharina latissima by broiler chicken’s caecal microbiota

This study investigated seasonal variations in the composition of the kelp species Saccharina latissima cultivated on the Swedish west coast and, using an in vitro fermentation system, evaluated the effect of fermented whole S. latissima biomass or biomass components on the gut microbiota of broiler chickens. Caecal contents of six Ross 308 broilers fed a standard wheat and soy-based diet were retrieved on two different occasions, with three birds sampled per occasion. Two in vitro fermentation batches (A, B) were established using caecal contents as inoculum, and whole S. latissima, ethanol-washed S. latissima, laminarin extract or inulin (control) as substrate. Total short-chain fatty acid (SCFA) content, gas production, pH and changes in microbiota composition were studied after 6, 12 and 24 h of fermentation. Analysis of seasonal variations revealed that S. latissima harvested in June had the highest laminarin content and lowest ash and crude protein content. Broiler microbiota, SCFA profile, gas production and pH mainly varied depending on fermentation inoculum, but there were also some variations depending on substrate. For instance, uncultured bacterium from Clostridiales_vadinBB60_group showed higher relative abundance (RA) in batch A, while Faecalibacterium showed higher RA in batch B. Whole and ethanol-washed S. latissima resulted in highest RA of unclassified Ruminococcaceae and Tyzzerella for both batches, while ethanol-washed S. latissima and laminarin gave highest RA of Erysipelatoclostridium. Inulin resulted in highest RA for the genus Subdoligranulum. Acetic, n-butyric and propionic acid were the main fermentation products and total SCFA level was higher in batch B. Within batch B, inulin and laminarin generated higher levels of acetic and butyric acid. When using inulin and laminarin, gas production was lower in batch B compared with batch A. In summary, this study showed that S. latissima is a good source of laminarin, especially when harvested in summer. Within the in vitro system, the microbiota was affected by different substrates, but inoculum source was identified as an important contributor to microbial community development during fermentation.

ANALYSIS OF COCOA FERMENTATION WITH THE ADDITION OF YEAST AND LACTIC ACID BACTERIA

Abstract One of the factors that affect the quality of cocoa beans is post-harvest handling such as the fermentation process. Fermentation plays an important role in determining the final quality of dried cocoa beans. Chocolate flavors can be produced from microbial fermentation from high-quality cocoa bean raw materials by utilizing microbes. This study aims to calculate the number of microbes at the beginning and end of the cocoa bean fermentation process, observing the pH value, temperature, and color of cocoa beans. The treatment carried out is a fermentation variation consisting of: (1) natural fermentation or without the addition of microorganisms; (2) controlled fermentation with the addition of microorganisms consisting of Saccharomyces cerevisiae, Lactic Acid Bacteria simultaneously added at the beginning of fermentation. The addition of microorganisms is 106 CFU / 1kg of cocoa beans each. Fermentation is carried out in a fermentation box with a capacity of 1 kg of fresh cocoa, at room temperature (33-35oC), for 4 days. The analysis carried out includes calculating the number of microbes at the beginning and end of fermentation, measuring pH, and organoleptic observations of the color of fermented cocoa beans. The results of the experiment can be concluded that there is an increase in the addition of mixed inoculum (Saccharomyces cerevisiae and Lactobacillus lactis) affecting the influence of chemical changes of the substrate during fermentation; the temperature value in cocoa fermentation ranges from 30 – 32 oC, the pH value in cocoa fermentation does not have a significant increase; and the color of cocoa beans from mixed inoculum fermentation is close to good with a dominant brown color against purple

Investigation into the treatment and resource recovery of rifamycin mycelial dreg with thermal alkaline pretreatment-anaerobic digestion

Rifamycin, a highly potent drug for the treatment of tuberculosis should raise environmental concerns due to its massive production of mycelial dreg (RMD). The RMD treatment by anaerobic digestion (AD) is a highly promising endeavor, but has still far from explicit. Herein, the thermal alkaline pretreatment (TAP)-AD process with RMD as substrate was performed. The optimal temperature, pH, and reaction time for TAP were 140 °C, 12, and 3 h, respectively. The optimal RMD concentration (1%) and inoculation ratio (2:1, sludge: RMD, mass ratio) were subsequently determined, leading to an increase of 86.4% in cumulative methane production. Correspondingly, a functional core taxa including fermentative bacteria and methanogens was enriched. Molecular ecological network (pMEN) revealed an ecological niche-based functional redundancy, which facilitated the efficiency and stability of the AD system. Notably, representative draft genome recovered from raw RMD possessed the potential fermentation capability, and the phosphotransferase component for carbohydrate transport may not be affected by rifamycin-B according to the results of molecular docking. Taking these factors, an innovative insight into the natural suitability of RMD as native fermentation inoculum was carefully presented. This study clarifies the feasibility of TAP-AD in the treatment of RMD. Moreover, it contributes to a deeper understanding of the ecological properties and microbial mechanisms in AD systems.

Investigating the role of Lactiplantibacillus plantarum vs. spontaneous fermentation in improving nutritional and consumer safety of the fermented white cabbage sprouts.

Brassicaceae sprouts are promising candidates for functional food because of their unique phytochemistry and high nutrient density compared to their seeds and matured vegetables. Despite being admired for their health-promoting properties, white cabbage sprouts have been least explored for their nutritional significance and behavior to lactic acid fermentation. This study aimed to investigate the role of lactic acid fermentation, i.e., inoculum vs. spontaneous, in reducing intrinsic toxicants load and improving nutrients delivering potential of the white cabbage sprouts. White cabbage sprouts with a 5-7cm average size were processed as raw, blanched, Lactiplantibacillus plantarum-inoculated fermentation, and spontaneous fermentation. Plant material was dehydrated at 40°C and evaluated for microbiological quality, macronutrients, minerals, and anti-nutrient contents. The results indicate L. plantarum inoculum fermentation of blanched cabbage sprouts (IF-BCS) to increase lactic acid bacteria count of the sprouts from 0.97 to 8.47 log CFU/g. Compared with the raw cabbage sprouts (RCS), inoculum fermented-raw cabbage sprouts (IF-RCS), and spontaneous fermented-raw cabbage sprouts (SF-RCS), the highest content of Ca (447mg/100g d.w.), Mg (204mg/100g d.w.), Fe (9.3mg/100g d.w.), Zn (5mg/100g d.w.), and Cu (0.5mg/100g d.w.) were recorded in IF-BCS. L. plantarum-led fermentation of BCS demonstrated a reduction in phytates, tannins, and oxalates contents at a rate of 42%, 66%, and 53%, respectively, while standalone lactic acid fermentation of the raw sprouts reduced the burden of anti-nutrients in a range between 32 and 56%. The results suggest L. plantarum-led lactic acid fermentation coupled with sprout blanching is the most promising way to improve the nutritional quality and safety of the white cabbage sprouts.

Performance of a mixed inoculum of sludge and pit mud for short and medium-chain fatty acids production: Insight into key microbiome and functional potential in anaerobic fermentation inoculum

In this study, medium-chain fatty acids (MCFA) production from food waste with ethanol as electron donor using three different inoculants (active sludge, pit mud and mixture of sludge and pit mud). The results showed that the R3 (mixed inoculum of sludge and pit mud) produced 8539.1 mg COD/L of MCFA, which was significantly higher than that produced by R1 (active sludge, 2712.6 mg COD/L) and R2 (pit mud, 3585.9 mg COD/L). The major MCFA was caproate and heptanoate, and the short-chain fatty acids (SCFA) and MCFA selectivity reaches 69.2%. Microbial community analysis revealed that the relative abundance levels of Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_12 and Oscibacter were positively correlated with MCFA production. Further analysis of the enzymes related genes involved in the MCFA biosynthesis indicates that they were mainly related to enzymes of Clostridium, Oscibacter and Ruminiclostridium. These were the key genera involved in the chain elongation process. Metagenomic analysis revealed that fatty acid biosynthesis (FAB) pathway was the main pathway of MCFA synthesis in all three fermentation reactors. The abundance levels of all FAB pathway related-genes and MCFA functional microorganisms were higher in R3. Additionally, the enrichment of the main gene abundance of metabolic pathway revealing that the mixed inoculum of sludge and pit mud combined the ability of fatty acid biosynthesis and carbohydrate metabolism, with higher fermentation potential. Overall, this study provides new strategies and insights for MCFA production.

Production of Natural Dye from Macro Algae

Dye is an intensely colored complex organic substance used for colouring other materials. They can be synthesized artificially or obtained from natural products. Natural colours are also called biocolors since they are extracted from biological materials like fruits, vegetables, seeds, roots, insects and microorganisms. In this study, microbial fermentation using macro algae as substrate was utilized to extract dye. Different macro algae such as Chaetomorphaantennia, Gracilariacorticota and Ulva fasciata were collected from Kovalam, Mahabalipuram, Tamil Nadu and were used as a substrate for fermentation. Aspergillus nigerwas used as an inoculum for fermentation. SSF was carried out for 10 days and the dye was extracted. Quality of the colour was analysed by adding fixative and non fixative at different time intervals. Results revealed that the colour intensity was more in the addition of fixative. Different pigments such as chlorophyll a (20.625 mg/l) was found more in U.fasciata , chlorophyll b (12.486 mg/l) was to be more in G.corticata and high amount of total carotene was found in ( 14.701mg/l) in C.antennina and least was found in U.fasciata(3.39 mg/l). Among all seaweed substrates, C.antenninawas found to be the good one to impart colour

Effects of environmental factors on low temperature anaerobic digestion of pig manure

In this study, we investigated the inhibitory effect of low temperature on biogas fermentation system. Biogas fermentation inoculum was domesticated at 4 °C, and subsequently inoculated into pig manure feedstock in a batch biogas fermentation process. A low-temperature biogas fermentation system was maintained at 9 °C, and its abiotic factors, bacterial community, and archaeal community were determined. The results showed that (1) the biogas fermentation lasted for 160 days, with a total gas production of 19,150 ml, including N2 production of 11,370 ml, CO2 production of 3,534 ml, and CH4 production of 3,031 ml. (2) The average relative abundance of the primary dominant bacterium operational taxonomic unit (OTU) was 30%, with 100% similarity to Pseudomonas caeni , atypical denitrifying bacterium. The average relative abundance of the secondary dominant bacterium OTU was 20.36%, with 99% similarity to Clostridium cellulovorans, a typical cellulose- and hemicellulose-degrading bacterium. The average relative abundance of the primary dominant methanogenic archaeon OTU was 7.22%, with 99% similarity to Methanosphaera cuniculi, a typical methylotrophic methanogen, and the secondary dominant methanogenic archaeon OTU had an average relative abundance of 4.15%, with 98% similarity to Methanocorpusculum sinense, a typical hydrogenotrophic methanogen. (3) The primary dominant bacterial genus Pseudomonas exhibited highly significant negative correlations with the dominant biogas-producing microorganisms such as Clostridium, Terrisporobacter, Turicibacter, Methanosphaera, and Methanocorpusculum. We concluded that (1) high concentrations of abiotic factors such as ammonia nitrogen, acetic acid, and propionic acid were important indicators of relatively poor operation of low-temperature biogas fermentation systems, while (2) high numbers of MCG archaea and Pseudomonas were important biotic factors showing comparatively poor operation of the system.

Lactic acid from mixed food waste fermentation using an adapted inoculum: Influence of pH and temperature regulation on yield and product spectrum

Environmental conditions (pH and temperature) are expected to influence microbial community composition and product spectrum in mixed-culture food waste (FW) fermentation. However, some conditions may favour growth of multiple organisms that compete for common substrates or consume target metabolites. The inoculum plays an integral role in mixed-culture fermentation, but it is currently unknown how an adapted inoculum, known to selectively produce the target metabolite, would influence fermentation, and how environmental conditions could control fermentation outcomes. Therefore, this study assessed the effects of pH (uncontrolled vs. controlled pH 4.0–6.0) and temperature (35–60 °C) on lactic acid (LA) from synthetic mixed FW batch fermentation (80 gVS·L−1) utilising an adapted fermentation inoculum known to produce significant LA (10% inoculum volume). Concentrations of LA and competing organic acids were measured. Uncontrolled pH encouraged Lactobacillus growth but resulted in a low LA yield due to inhibitory conditions. Controlled pH 6.0 improved LA production but introduced LA consumption and competitive butyrate production. Observed butyrate production was dependent on pH and temperature and correlated with the growth of Clostridium Sensu Stricto 12. At pH 6.0 and 50 °C, observable LA consumption was eliminated, and the LA yield was maximised at 0.55 gLA·gVS−1 (39 gLA·L−1) while Lactobacillus remained dominant. The adapted inoculum effectively promoted LA production, while pH and temperature regulation were effective control levers to target LA.

Simulated elephant colon for cellulose extraction from sugarcane bagasse: An effective pretreatment to reduce chemical use

Sugarcane bagasse (SCB) is an abundant by-product from sugar production and promising biomass for cellulose extraction. Simulated elephant colon pretreatment (SEP) to reduce chemical use in cellulose extraction from SCB was investigated using elephant dung as fermentation inoculum. The 16S rRNA gene sequences showed microorganisms in elephant dung that corresponded to metabolites during pretreatment. Organic acid accumulation in the fermentation broth was confirmed by the presence of lactic, acetic, propionic and butyric acids. Lignin peroxidase, manganese peroxidase and xylanase detected during the pretreatment enhanced lignin removal. The SEP fiber showed increased cellulose content, while lignin content decreased with reduced bleaching time from 7 to 5 h and high whiteness and crystallinity indices. Lignin removal was also confirmed by Fourier transform infrared spectroscopy. Scanning electron microscopy revealed increasing internal surface area through opening up the fiber structure. SEP offered an efficient and promising approach for cellulose fiber extraction with reduced use of chemicals for the bleaching process.

Untargeted Metabolomics Combined with Solid Phase Fractionation for Systematic Characterization of Bioactive Compounds in Hemp with Methane Mitigation Potential.

This study systematically evaluates the presence of methane mitigating metabolites in two hemp (Cannabis sativa L.) varieties, Futura 75 and Finola. Hemp metabolites were extracted with methanol and fractionated using Solid Phase Extraction (SPE). Extracts, fractions, and the remaining pulp were screened for their methane mitigating potential using an in vitro model of rumen fermentation. The bioactive metabolites were identified with Liquid Chromatography-Mass Spectrometry (LC-MS). When incubated with a standard feed (maize silage), the extract of Futura 75 significantly reduced methane production compared to that of control (without added extract) and without negative effects on feed degradability and volatile fatty acid patterns. The compounds responsible for the methane mitigating effect were assigned to flavonoid glycosides. However, none of the fractions of Futura 75 or the pulp exhibited similar effect on methane emission. Butyric acid concentration in the fermentation inoculum was significantly increased, which could indicate why methane production was higher, when incubated with the fractions and the pulp. The extract of Finola did not show a similar significant effect, however, there was a numerical tendency towards lower methane production. The difference in methane mitigating properties between Cannabis sativa L. Futura 75 and Finola, could be related to the content of bioactive flavonoids.

Anaerobic Mesophilic Digestion of Typha Latifolia Suspensions Using the Fermented Waste of Yeast Production as Fermentation Inoculum

Anaerobic Mesophilic Digestion of Typha Latifolia Suspensions Using the Fermented Waste of Yeast Production as Fermentation Inoculum

Supplementing Glycerol to Inoculum Induces Changes in pH, SCFA Profiles, and Microbiota Composition in In-Vitro Batch Fermentation

Glycerol was generally added to the inoculum as a cryoprotectant. However, it was also a suitable substrate for microbial fermentation, which may produce more SCFAs, thereby decreased pH of the fermentation broth. This study investigated the effect of supplementing glycerol to inoculum on in vitro fermentation and whether an enhanced buffer capacity of medium could maintain the pH stability during in vitro batch fermentation, subsequently improving the accuracy of short chain fatty acids (SCFAs) determination, especially propionate. Two ileal digesta were fermented by pig fecal inoculum with or without glycerol (served as anti-frozen inoculum or frozen inoculum) in standard buffer or enhanced buffer solution (served as normal or modified medium). Along with the fermentation, adding glycerol decreased the pH of fermentation broth (p &lt; 0.05). However, modified medium could alleviate the pH decrement compared with normal medium (p &lt; 0.05). The concentration of total propionic acid production was much higher than that of other SCFAs in anti-frozen inoculum fermentation at 24 and 36 h, thereby increasing the variation (SD) of net production of propionate. The α-diversity analysis showed that adding glycerol decreased Chao1 and Shannon index under normal medium fermentation (p &lt; 0.05) compared to modified medium (p &lt; 0.05) along with fermentation. PCoA showed that all groups were clustered differently (p &lt; 0.01). Adding glycerol improved the relative abundances of Firmicutes, Anaerovibrio, unclassified_f_Selenomonadaceae, and decreased the relative abundance of Proteobacteria (p &lt; 0.05). The relative abundances of Firmicutes, such as Lactobacillus, Blautia and Eubacterium_Ruminantium_group in modified medium with frozen inoculum fermentation were higher than (p &lt; 0.05) those in normal medium at 36 h of incubation. These results showed that adding glycerol in inoculum changed the fermentation patterns, regardless of substrate and medium, and suggested fermentation using frozen inoculum with modified medium could maintain stability of pH, improve the accuracy of SCFA determination, as well as maintain a balanced microbial community.

Integrated Chemical Biochemical Technology to Reduce Ammonia Emission from Fermented Municipal Biowaste

A new eco-friendly process is reported, the implementation of which at the EU level could reduce ammonia and greenhouse gas emissions from fermented biowaste by over 1 Gt yr–1. The present work reports the case study of municipal biowaste (MBW). The process is based on the use of soluble bio-organic substances (SBOs) as auxiliaries in the anaerobic fermentation of MBW to produce biogas and digestate with reduced ammonia content. The SBO-assisted process enables a virtuous biowaste cycle, where MBW is sequentially fermented under anoxic conditions, the digestate is composted, and the compost generated is hydrolyzed, yielding SBO, which is recycled to the anaerobic fermentation reactor at 0.2% concentration. The results show that depending on the MBW source, fermentation inoculum, and SBO concentration in the fermentation slurry, about 40% reduction of ammonium in the digestate is achieved, whereas the control fermentation without SBO exhibits up to 11% ammonia increase. The microbial community and biogas production are not significantly affected by SBO addition. The data are consistent with biological and chemical processes occurring in SBO-assisted fermentation. These comprise ammonia production by protein hydrolysis catalyzed by proteolytic bacteria and ammonia oxidation to N2 catalyzed by SBOs. The results confirm the benefit provided by the use of SBOs to reduce the environmental impact of biowaste. These encourage the implementation of SBO-assisted fermentation in the real operational environment.

In vitro Fermentation Reveals Changes in Butyrate Production Dependent on Resistant Starch Source and Microbiome Composition.

One of the primary benefits associated with dietary resistant starch (RS) is the production of butyrate by the gut microbiome during fermentation of this fiber in the large intestine. The ability to degrade RS is a relatively rare trait among microbes in the gut, seemingly confined to only a few species, none of which are butyrate producing organisms. Thus, production of butyrate during RS fermentation requires a network of interactions between RS degraders and butyrate producers. This is further complicated by the fact that there are multiple types of RS that differ in their structural properties and impacts on the microbiome. Human dietary intervention trials with RS have shown increases in fecal butyrate levels at the population level but with individual to individual differences. This suggests that interindividual differences in microbiome composition dictate butyrate response, but the factors driving this are still unknown. Furthermore, it is unknown whether a lack of increase in butyrate production upon supplementation with one RS is indicative of a lack of butyrate production with any RS. To shed some light on these issues we have undertaken an in vitro fermentation approach in an attempt to mimic RS fermentation in the colon. Fecal samples from 10 individuals were used as the inoculum for fermentation with 10 different starch sources. Butyrate production was heterogeneous across both fecal inocula and starch source, suggesting that a given microbiome is best suited to produce butyrate only from a subset of RS sources that differs between individuals. Interestingly, neither the total amount of RS degraders nor butyrate producers seemed to be limiting for any individual, rather the membership of these sub-populations was more important. While none of the RS degrading organisms were correlated with butyrate levels, Ruminococcus bromii was strongly positively correlated with many of the most important butyrate producers in the gut, though total butyrate production was strongly influenced by factors such as pH and lactate levels. Together these results suggest that the membership of the RS degrader and butyrate producer communities rather than their abundances determine the RS sources that will increase butyrate levels for a given microbiome.

Techno-Economic Assessment of On-Farm Anaerobic Digestion System Using Attached-Biofilm Reactor in the Dairy Industry

In this study, a techno-economic assessment of an on-farm biogas system using an anaerobic biofilm reactor utilizing cow manure as a fermentation substrate was evaluated. A projection model was developed using Microsoft Excel software with three outputs, the size and dimension of a bioreactor, experimental microbial kinetic studies, and the economic studies based on the experimental results. Characterization analysis of cow manure wastewater showed the total solid (TS), total volatile solid (TVS), total carbohydrate (TC), chemical oxygen demand (COD), and pH values which were 10.95 g/L, 8.65 g/L, 6.65 g/L, 57.80 g/L, and 7, respectively. Using the modified Gompertz equation for the microbial studies, it was found that, at 37 °C and 20 days hydraulic retention time (HRT), the biogas yield was 934.54 mL/gVS, the volume of biogas produced was 11.28 m3/d, and 22.56 kWh of electricity was generated. The Gompertz prediction helps to determine the optimal HRT for the system so that the microorganisms are at their optimum stage to produce biogas. The economic analysis was done, and the results illustrated that, when the rate of cow manure produced was at 55 L/day.cow, the net present value (NPV) was RM 611,936.09, with a 13% internal rate of return (IRR), 0.14 return on investment (ROI), and 7.02 years of payback period (PP). By developing a techno-economic assessment that included all the necessary parameters such as sizing of the bioreactor, microbial kinetic studies, and economics of the plant, farmers could easily implement the system into their farms. This model showed that the anaerobic digestion system utilizing an attached biofilm with cow manure as a fermentation inoculum and substrate was applicable on an industrial scale to generate electricity and reutilize to the farm, at the same time generating additional income from the production of fertilizer.

Plant-based traditional foods and beverages of Ramotswa Village, Botswana

Background and objectivesDifferent communities have various types of edible plants at their nearby ecology from which they process their traditional foods that make the basis of diversified diets for food and nutrition security. Exploration of various ethnic traditional foods knowledge will have an immense contribution for preservation and sustainability of the traditional food system and culture. The objectives of this research were to investigate and document the edible plant type used and description on the processing of plant-based traditional foods/dishes and beverages of the Ramotswa village, Botswana. Majority of the Ramotswa village residents belong to the Balete tribe.MethodologyQuestionnaire interviews and focus group discussions (FGD) were used in the documentations of edible plants type, methods involved in the processing, values, challenges, and the seasonal availability.Results and discussionThere are 50 wild edible plants used and most are available during rainy season. Maize, sorghum, beans, cooking melon, watermelon, and pumpkin are widely used domesticated crops. The edible part of wild plants is utilized in different ways. Some consumed after minor processing and some as cooked, boiled, recipe in traditional dishes, inoculum in fermentation, substrate in traditional beverages, and medicinal plants. Food safety concerns were indicated for few products. High temperature and shortage of rainfall are making some edible plants scarce. For some, preparation takes a long time; and when processing is not properly done, unpleasant odor, bitter taste, and mold growth can result, particularly for traditional beverages. Even though, most traditional foods/dishes and beverages are still consumed and enjoyed by the communities, there are worries that the young generation has limited knowledge and skills to process and utilize them.ConclusionsMost plant-based traditional foods/dishes consumed are low in sugar and fat, but are wholesome (whole grains, with dietary fibers) with high potential for diet diversification. The documentation provided will help to create awareness for preservation of the traditional foods/dishes and beverage culture, and as a baseline information for further studies for those nutrient and bioactive compound data are not available.

Effects of Lactobacillus plantarum Inoculum on the Fermentation Rate and Rice Noodle Quality.

To accelerate the fermentation rate and reduce the adverse effects of undesirable microorganism contamination on rice noodle quality, the pure inoculum fermentation method was used to produce fermented rice noodles. The results indicated that the pure inoculum fermented rice slurry required 10 h to reach a stable pH value. While, the pH value of the natural, pure and natural inoculum fermented rice slurries required 54, 18 and 20 h to stabilize, respectively. Free amino acids and lactic acid concentrations of the pure inoculum fermented rice slurry were higher than those of the natural and natural inoculum fermented rice slurries. The pure inoculum fermentation modified the proximate composition and lowered the pasting viscosities of the rice flour. The texture, cooking and eating qualities of the pure inoculum fermented rice noodles were similar to those of the natural fermented ones. In addition, the pure inoculum fermented rice noodles had higher relative contents of aldehydes than other fermented rice noodles and thus had a better flavor. Therefore, pure inoculum fermentation accelerated the fermentation rate and improved the rice noodle flavor while maintaining the texture, cooking and eating qualities of the rice noodles.

Genotypic Characterization of Rhizopus species from Tempeh and Usar: Traditional Inoculum of Tempeh in Indonesia

Abstract. Soybeans tempeh (tempeh) is processed by fermentation using Rhizopus spp. Tempeh is an important source of protein in Indonesia. The traditional inoculum in fermentation locally is known as Usar which is made from the leaves of Hibiscus tiliaceus. However, Rhizopus information from Usar is still limited. Therefore, this study aims to identify and investigate the genetic diversity of Rhizopus species from Usar and tempeh based on the Internal Transcribed Spacer (ITS) sequence and the Random Amplified Polymorphic DNA (RAPD) markers. Twenty-three Rhizopus strains were isolated from Usar and ten Rhizopus strains were isolated from tempeh. Based on ITS sequences, the isolates were similar to R Rhizopus microsporus (30 isolates) and Rhizopus delemar (3 isolates) with 98-99% similarity. The genetics of R. microsporus and R. delemar are varied and different from the genetics of R. microsporus from tempeh. The growth temperature of R. microsporus varies from 33 to 48°C and R. delemar can grow to a maximum at 33°C. The role of R. microsporus and R. delemar from Usar in determining the quality of tempeh is still limited. Therefore, it needs to be investigated further.