Biosynthesis of Xanthan Gum by Xanthomonas campestris Using Cane Molasses as a Carbon Source

The objective of the present study was to study the optimization conditions for the production of xanthan by Xanthomonas campestris from pre-treated sugarcane molasses. In the study, the optimization was carried out for different parameters including pH, temperature, and incubation time for the pre-treated sugarcane molasses. The age of inoculums and time of culture growth (6, 12, 18 and 24 hrs), size of inoculums (2%, 5%, 7.5% and 10%), pH (6.6, 6.8, 7.0 and 7.2) and temperature (25°C, 28°C, 30°C, 32°C and 37°C) were studied. It was observed that the xanthan production was maximal with 7.5% (v/v) inoculums, pH. 7 at 30°C for 48 hrs. The study suggested that cane molasses is an appropriate agro-industrial substrate for xanthan gum fermentations, and further scale-up study is needed for gum production in the stirred fermenter.

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Biosynthesis of xanthan gum on wastewater from confectionary industry

Analecta Technica Szegedinensia ◽

10.14232/analecta.2014.2.13-17 ◽

2014 ◽

Vol 8 (2) ◽

pp. 13-17 ◽

Cited By ~ 2

Author(s):

Bojana Bajić ◽

Jelena Dodić ◽

Zorana Rončević ◽

Jovana Grahovac ◽

Siniša Dodić ◽

...

Keyword(s):

Xanthan Gum ◽

Xanthomonas Campestris ◽

Quantitative Characteristic ◽

Environmental Pollutants ◽

High Viscosity ◽

Organic Content ◽

Low Concentrations ◽

Xanthan Production ◽

Valuable Product ◽

High Degree

Xanthan gum is one of the major commercial biopolymers employed in many industrial processes owing to its unique physical properties such as a high degree of pseudoplasticity and high viscosity even at low concentrations. Commercially available xanthan gum is relatively expensive due to glucose or sucrose being used as the sole carbon source for its production and cost reduction could be achieved by using less expensive substrates, such as food industrial wastewaters. Effluents from the confectionery industry, because of its high organic content, are significant environmental pollutants and before their release into environment it is necessary to purify them. The present study examines xanthan production by Xanthomonas campestris under aerobic conditions on wastewaters from five different factories of the confectionery industry. Xanthan yield was obtained as a quantitative characteristic of the process and was in the range between 4.28 g/L and 10.03 g/L and its quality is determined by following rheological characteristics of obtained cultivation media. The results obtained in this study indicate that wastewater from confectionary industry can be used as the basis of media for the production of this highly valuable product.

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Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses

AMB Express ◽

10.1186/s13568-021-01257-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Song Wang ◽

Ran Tian ◽

Buwei Liu ◽

Hongcai Wang ◽

Jun Liu ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

High Performance ◽

Ethanol Yield ◽

Starter Culture ◽

Market Price ◽

Sugarcane Molasses ◽

Engineering Strain ◽

Carbohydrate Utilization ◽

Cane Molasses

AbstractSugarcane molasses are considered a potential source for bioethanol’s commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT–qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter’s pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.

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