scholarly journals Evaluation of conditions for fermentation of fish offal

1995 ◽  
Vol 4 (1) ◽  
pp. 11-17
Author(s):  
T. Mikael Lassén

Conditions for the lactic acid fermentation of fish offal were evaluated regarding the effect of substrate concentration (2, 5 and 10% dextrose), preacidification with lactic acid (initial pH of 6.8, to 6.5 or 6.0), and inoculum size of Lactobacillus plantarum (107 , 108 and 109 colony forming units (cfu)/g). pH and lactic acid production were monitored during a two-week storage period. A small-scale silo for fermenting fish offal was also constructed, and measurement of redox potential was evaluated as a means to estimate bacterial growth conditions. The most favourable conditions for fermentation, manifested by a low and stable pH and high lactic acid production, were achieved with an inoculum size of 108 cfu/g and 5% dextrose. Preacidification did not affect final pH. Redox potential was shown to give a reliable estimate of growth conditions for bacteria under anaerobic conditions by rapidly falling to below -550mV in silage with a high lactic acid concentration.

2022 ◽  
Vol 16 (1) ◽  
pp. 12
Author(s):  
Nor Atikah Husna Ahmad Nasir ◽  
Nurul Syafiqah Mohd Yaminudin ◽  
Atikah Kamaludin ◽  
Sharir Aizat Kamaruddin ◽  
Siti Nurbalqis Aziman

For ages, pure sugars or edible crops have produced lactic acid. However, a major concern on lactic acid production lies in the cost of the raw materials used. Thus, an alternative to overcome this situation is urgently needed. Characterization of banana peels shows that it contains promising sugar that can be utilized for lactic acid production, which are xylose (0.774 g/L), glucose (0.756 g/L) and fructose (0.532 g/L). Thus, this study aims to screen the potential of banana peel as a substrate by using Rhizopus oryzae through batch fermentation for lactic acid production, as R. oryzae can synthesize lactic acid in low nutrient requirements. Two-level factorial analysis was designed to screen the effects of moisture content (60% and 80%), temperature (27 °C and 40 °C), pH (4.5 and 6.5) and inoculum size (1x104 spores/mL and 1x108 spores/g) on the lactic acid production. Based on the Two-level factorial (2LF) analysis, the highest lactic acid production of 0.0813 g/L was detected at 80 % moisture content, pH 4.5, the temperature of 27 °C and inoculum size of 1x104 spores/g. The findings show that most of the conditions have a significant difference between each other (p<0.05). Therefore, the fermentation of banana peels by R. oryzae could be a promising method to produce a lactic acid concentration.


2016 ◽  
Vol 18 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Hamidreza Ghafouri Taleghani ◽  
Ghasem D. Najafpour ◽  
Ali Asghar Ghoreyshi

Abstract In batch fermentation of whey, selection of suitable species at desired conditions such as substrate, product concentrations, temperature and inoculum size were investigated. Four Lactobacillus species and one Lactococcus species were screened for lactic acid production. Among them L. bulgaricus ATCC 11842 were selected for further studies. The optimal growth of the selected organism for variable size of inocula was examined. The results indicated that inoculum size had insignificant effect on the cell and lactic acid concentration. The effect of temperature was also studied at 32, 37, 42 and 47°C. Results showed that the concentration of cell dry weight increased with increment of temperature from 32 to 42°C. The maximum cell and lactic acid concentration was obtained at 42°C. The effect of initial substrate concentration on lactic acid production was also examined. The optimum initial lactose concentration was found to be 90 g/l.


1994 ◽  
Vol 21 (1) ◽  
pp. 23-26 ◽  
Author(s):  
A. Hallgren ◽  
A. Oliveby ◽  
S. Twetman

The lactic acid production in suspensions of plaque collected adjacent to orthodontic brackets retained with a glass ionomer cement (GIC), or a resin-based composite was investigated using a split-mouth technique. Forty-eight-hour-old plaque was collected at 3, 8, and 28 days, and 3 months after the onset of orthodontic treatment. Acid fermentation was induced by glucose and the L(+)-lactic acid concentrations were determined enzymatically after a 30-minute incubation period. Significantly (P<0·05) lower levels of lactic acid were found in plaque from GIC-retained brackets compared with the composite controls at the 28 days and 3 months sampling occasions, respectively. The results suggest that the use of GIC as a bonding agent in orthodontics can be beneficial for patients assessed at risk of caries development.


BioResources ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1379-1389
Author(s):  
Yingnan Cao ◽  
Juan Wang ◽  
Qunhui Wang ◽  
Jianguo Liu ◽  
Tingxi Liu ◽  
...  

Efficient pretreatment and enzymatic hydrolysis is critical to achieve effective utilization of lignocellulosic biomass. In this study, the cellulase composition for lignocellulosic biomass hydrolysis was strategically optimized to improve the efficiency of vinasse saccharification and thus enhance L-lactic acid production. The results showed that the supplementation of β-glycosidase (BG) increased sugar production, and the glucose concentration exceeded cellobiose concentration after 48 h of hydrolysis. These results suggested that the addition of BG aided the hydrolysis of cellobiose and reduced the inhibitory effects caused by sugar accumulation. After 72 h to 96 h of hydrolysis, the BG supplementation improved cellobiose and glucose production by 25.7% and 27.4%, respectively. The effect of BG supplementation on L-lactic acid production during the fermentation of microwave-alkali pretreated vinasse was also investigated. Here, the L-lactic acid production from simultaneous saccharification and fermentation (SSF) with the addition of BG was 20.8% higher than that without BG addition, and was also 37.0% higher than production from separate hydrolysis and fermentation with BG addition. These results indicated the utilization efficiency of lignocellulosic biomass for L-lactic acid production could be enhanced by supplementation of BG in SSF.


2014 ◽  
Vol 17 (2) ◽  
pp. 65-71
Author(s):  
Nhat Minh Dang ◽  
Trung Quang Nguyen

This study aimed to evaluate the effect of various factors on the yield of lactic acid fermentation using sap from sugar palm and Lactobacillus casei. The sugar palm sap after harvesting, pretreatment was added with ammonium sulphate, calcium carbonate and microbial culture at density of 109 cells/ml and let fermented for acid lactic production. The results of the experiments showed that the culture size, amount of added ammonium sulphate and calcium carbonate had significant effect on lactic acid production. The most appropriate parameters determined were culture size of 5%, ammonium sulphate of 3.0 g/l and calcium carbonate of 4.0 g/l. Meanwhile, the optimum period of fermentation was 100 h, which gave the yield of lactic acid production of 22.30 g. Lactobacillus casei was considered to have lower ability to effectively produce lactic acid from sugar palm sap compared to Lactobacillus plantarum


Author(s):  
Ling Liu ◽  
Danlu Yang ◽  
Zhiyu Zhang ◽  
Tao Liu ◽  
Guoquan Hu ◽  
...  

Pediococcus acidilactici is commonly used for pediocin production and lactic acid fermentation. However, high-efficiency genome editing tool is unavailable for this species. In this study, we constructed the endogenous subtype II-A CRISPR-Cas system-based genome interference plasmids which carried a “Repeat-Spacer-Repeat” cassette in the pMG36e shuttle vector. These plasmids exhibited self-interference activities in P. acidilactici LA412. Then, the genome-editing plasmids were constructed by cloning the upstream/downstream donor DNA into the corresponding interference plasmids to exert high-efficiency markerless gene deletion, gene integration, and point mutation in P. acidilactici LA412. We found that endogenous CRISPR-mediated depletion of the native plasmids enhanced the cell growth, and integration of a L-lactate dehydrogenase gene into the chromosome both enhanced cell growth and lactic acid production. IMPORTANCE A rapid and precise genome editing tool will promote the practical application of Pediococcus acidilactici , one type of lactic acid bacteria with excellent stress tolerance and probiotic characteristics. This study established a high-efficiency endogenous CRISPR-Cas system-based genome editing tool for P. acidilactici and achieved different genetic manipulations, including gene deletion, gene insertion, mononucleotide mutation, and endogenous plasmid depletion. The engineered strain edited by this tool showed significant advantages in cell growth and lactic acid fermentation. Therefore, our tool can satisfy the requirements for genetic manipulations of P. acidilactici , thus making it a sophisticated chassis species for synthetic biology and bioindustry.


RSC Advances ◽  
2018 ◽  
Vol 8 (55) ◽  
pp. 31267-31274 ◽  
Author(s):  
Suan Shi ◽  
Jing Li ◽  
Wenjian Guan ◽  
David Blersch

Fish manure wastes are an effective nutrient source for lactic acid production using simultaneous saccharification and fermentation.


2017 ◽  
Vol 66 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Guoping Lv ◽  
Chengchuan Che ◽  
Li Li ◽  
Shujing Xu ◽  
Wanyi Guan ◽  
...  

The traditional CaCO3-based fermentation process generates huge amount of insoluble waste. To solve this problem, we have developed an efficient and green D-lactic acid fermentation process by using ammonia as neutralizer. The 106.7 g/l of D-lactic acid production and 0.89 g/g of consumed sugar were obtained by Sporolactobacillus inulinus CASD with a high optical purity of 99.7% by adding 100 mg/l betaine in the simple batch fermentation. The addition of betaine was experimentally proven to protect cell at high concentration of ammonium ion, increase the D-lactate dehydrogenase specific activity and thus promote the production of D-lactic acid.


Author(s):  
Arjun Ghimire ◽  
Stuti Sapkota

Fish pickle was prepared from Rohu (Labeo rohita) by fermentation for 15 days and the changes in biomass growth, lactic acid production, and pH were evaluated. The data obtained were fitted in two most widely accepted microbial growth models: Modified Gompertz, and Logistic model and three well known lactic acid production models: Luedeking-Piret, Monteagudo et al., and Balannec et al. model for lactic acid fermentation. Model constants and coefficients were determined by a nonlinear regression method. All the models were validated using statistical parameters namely, coefficient of determination (R2), root mean square error (RMSE), reduced chi-square (χ2) and the reduced sum of squares (RSS). The results revealed that the viable cell counts increased from 0.91×107 cfu/ml to 9×109 cfu/ml after nine days of fermentation. The lactic acid increased by about 11.6 times in 12 days and remained constant for the rest of the fermentation period. The pH decreased from 6.5 to 4.2 on the 15th day of fermentation and then increased slightly till the final day of fermentation. The Logistic model and Luedeking-Piret model were best fitted to describe the biomass growth and lactic acid production by LAB during the fermentation period of pickle. The growth-associated and non-growth associated coefficients were determined to be 0.813 and 0.005, respectively. Based on these estimated parameters, it is concluded that lactic acid production in the fish pickle was a mixed type.


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