Microbial production of xanthan gum from forage sorghum straw (FSS) was investigated. The important aspect investigated was the synthesis of xanthan gum using hemicellulose as a substrate (hemicellulose-derived xanthan), a process that has been relatively underexplored in the existing literature. Xanthomonas campestris ATCC 33913 and an isolated strain from orange peel, identified as X. axonopodis, were utilized for xanthan production. The FSS hydrolysate obtained by treatment under 120 °C for 30 min and overliming, yielded xanthan gum concentration of 7.1 g/L for X. campestris and 6.9 g/L for X. axonopodis. The lower molecular weights of xanthan gum produced from FSS (590 kDa for X. campestris and 550 kDa for the isolated X. axonopodis), compared to those from glucose suggest distinct advantages for specialized applications. Xanthan gum from FSS also possessed a higher ratio of acetate to pyruvate, ranging from 1.5:1 to 1.91:1 for X. axonopodis and from 1.33:1 to 1.75:1 for X. campestris. This characteristic renders it an attractive choice for certain applications in the food industry. By utilizing this strain, 11.71 g of hemicellulose-derived xanthan gum and 13.8 g of cellulose-derived xanthan gum per 100 g of FSS were obtained, indicating a conversion rate of 25.51 %.
In this study, 398 Iranian cancer patients completed the 15-item Templer's Death Anxiety Scale (TDAS). Tests of internal consistency, principal components analysis, and confirmatory factor analysis were conducted to assess the internal consistency and factorial validity of the Persian TDAS. The construct reliability statistic and average variance extracted were also calculated to measure construct reliability, convergent validity, and discriminant validity. Principal components analysis indicated a 3-component solution, which was generally supported in the confirmatory analysis. However, acceptable cutoffs for construct reliability, convergent validity, and discriminant validity were not fulfilled for the three subscales that were derived from the principal component analysis. This study demonstrated both the advantages and potential limitations of using the TDAS with Persian-speaking cancer patients.