Physicochemical Pretreatment of Vietnamosasa pusilla for Bioethanol and Xylitol Production.

The consumption of fossil fuels has resulted in severe environmental consequences, including greenhouse gas emissions and climate change. Therefore, transitioning to alternative energy sources, such as cellulosic ethanol, is a promising strategy for reducing environmental impacts and promoting sustainable low-carbon energy. Vietnamosasa pusilla, an invasive weed, has been recognized as a high potential feedstock for sugar-based biorefineries due to its high total carbohydrate content, including glucan (48.1 ± 0.3%) and xylan (19.2 ± 0.4%). This study aimed to examine the impact of NaOH pretreatment-assisted autoclaving on V. pusilla feedstock. The V. pusilla enzymatic hydrolysate was used as a substrate for bioethanol and xylitol synthesis. After treating the feedstock with varying concentrations of NaOH at different temperatures, the glucose and xylose recovery yields were substantially higher than those of the untreated material. The hydrolysate generated by enzymatic hydrolysis was fermented into bioethanol using Saccharomyces cerevisiae TISTR 5339. The liquid byproduct of ethanol production was utilized by Candida tropicalis TISTR 5171 to generate xylitol. The results of this study indicate that the six- and five-carbon sugars of V. pusilla biomass have great potential for the production of two value-added products (bioethanol and xylitol).

Cellulosic Ethanol Production from Weed Biomass Hydrolysate of Vietnamosasa pusilla.

Lignocellulosic biomass can be used as a renewable and sustainable energy source to help reduce the consequences of global warming. In the new energy age, the bioconversion of lignocellulosic biomass into green and clean energy displays remarkable potential and makes efficient use of waste. Bioethanol is a biofuel that can diminish reliance on fossil fuels while minimizing carbon emissions and increasing energy efficiency. Various lignocellulosic materials and weed biomass species have been selected as potential alternative energy sources. Vietnamosasa pusilla, a weed belonging to the Poaceae family, contains more than 40% glucan. However, research on the applications of this material is limited. Thus, here we aimed to achieve maximum fermentable glucose recovery and bioethanol production from weed biomass (V. pusilla). To this end, V. pusilla feedstocks were treated with varying concentrations of H3PO4 and then subjected to enzymatic hydrolysis. The results indicated that after pretreatment with different concentrations of H3PO4, the glucose recovery and digestibility at each concentration were markedly enhanced. Moreover, 87.5% of cellulosic ethanol was obtained from V. pusilla biomass hydrolysate medium without detoxification. Overall, our findings reveal that V. pusilla biomass can be introduced into sugar-based biorefineries to produce biofuels and other valuable chemicals.

Morphological and Molecular Characterizations of Musa (ABB) 'Mali-Ong' in Thailand.

Musa (ABB) 'Mali-Ong' is an economically important banana cultivar in Thailand. We morphologically and molecularly characterized 'Nam Wa Mali-Ong'. Leaf blade width was the only statistically different morphological character among the clones. To determine genetic variation, nine 'Nam Wa Mali-Ong' clones were compared with 10 samples of Musa ABB, AA, and BB cultivars by fingerprinting using seven pairs of sequence-related amplified polymorphism (SRAP) and eight inter simple sequence repeat (ISSR) markers. The SRAP and ISSR primers generated 65 and 76 amplicons, respectively, of which 57 (87.7%) and 62 (81.6%) amplicons, respectively, were polymorphic; the polymorphic information content was 0.28-0.49. The SRAP data revealed two distinct groups: Group I, comprising two subgroups (one including all ABB samples and the other containing the BB genome accessions), and Group II, comprising the AA genome accessions. The ISSR data revealed two groups: Group I, which incorporated the AA (Hom Champa) genome, and Group II, consisting of two subgroups: Subgroup A, comprising only the AA (Hom Chan) accessions, and subgroup B, comprising all the ABB accessions and wild banana M. balbisiana (BB genome). The 'Nam Wa Mali-Ong' samples clustered together, regardless of the markers used. SRAP and ISSR markers will be useful for germplasm evaluation and future Musa (ABB) improvements.

Nutraceutical Difference between Two Popular Thai Namwa Cultivars Used for Sun Dried Banana Products.

Musa (ABB group) "Kluai Namwa" bananas (Musa sp.) are widely grown throughout Thailand. Mali Ong is the most popular Kluai Namwa variety used as raw material for sun-dried banana production, especially in the Bangkratum District, Phitsanulok, Thailand. The sun-dried banana product made from Nanwa Mali Ong is well recognized as the best dried banana product of the country, with optimal taste compared to one made from other Kluai Namwa varieties. However, the production of Mali Ong has fluctuated substantially in recent years, leading to shortages. Consequently, farmers have turned to using other Kluai Namwa varieties including Nuanchan. This study investigated the nutraceutical contents of two popular Namwa varieties, Mali Ong and Nuanchan, at different ripening stages. Nutraceuticals in the dried banana products made from these two Kluai Namwa varieties and four commercial dried banana products were compared. Results indicated that the content of moisture, total sugar, and total soluble solids (TSS) (°Brix) increased, while total solids and texture values decreased during the ripening stage for both Kluai Namwa varieties. Rutin was the major flavonoid found in both Namwa Mali Ong and Nuanchan varieties ranging 136.00−204.89 mg/kg and 129.15−260.38 mg/kg, respectively. Rutin, naringenin, quercetin and catechin were abundant in both Namwa varieties. All flavonoids increased with ripening except for rutin, gallocatechin and gallocatechin gallate. There were no significant differences (p < 0.05) in flavonoid contents between both varieties. Tannic acid, ellagic acid, gallic acid, chlorogenic acid and ferulic acid were the main phenolic acids found in Mali Ong and Nuanchan varieties, ranging from 274.61−339.56 mg/kg and 293.13−372.66 mg/kg, respectively. Phenolic contents of both varieties decreased, increased and then decreased again during the development stage. Dopamine contents increased from 79.26 to 111.77 mg/kg and 60.38 to 125.07 mg/kg for Mali Ong and Nuanchan, respectively, but the amounts were not significantly different (p < 0.5) between the two Namwa varieties at each ripening stage. Inulin as fructooligosaccharide (FOS) increased with ripening steps. Production stages of sun-dried banana products showed no statistically significant differences (p < 0.05) between the two Namwa varieties. Therefore, when one variety is scarce, the other could be used as a replacement in terms of total flavonoids, phenolic acid, dopamine and FOS. In both Namwa varieties, sugar contents decreased after the drying process. Sugar contents of the dried products were 48.47 and 47.21 g/100 g. The drying process caused a reduction in total flavonoid contents and phenolic acid at 63−66% and 64−70%, respectively. No significant differences (p < 0.05) were found for total flavonoid and phenolic contents between the dried banana products made from the two Namwa varieties (178.21 vs. 182.53 mg/kg and 96.06 vs. 102.19 mg/kg, respectively). Products made from Nuanchan varieties (24.52 mg/kg) contained significantly higher dopamine than that from Mali Ong (38.52 mg/kg). The data also suggest that the banana maturity stage for production of the sun dried products was also optimum in terms of high nutraceutical level.

Improved glucose recovery from durian peel by alkaline-catalyzed steam pretreatment.

Durian (Durio zibethinus Murr.) peel, as agricultural waste, is a potential under-utilized lignocellulosic biomass that is sufficiently available in Thailand. In this study, durian peel from monthong (D. zibethinus Murr. cv. Monthong) and chanee (D.zibethinus Murr. cv. Chanee) were subjected to pretreatment with sodium hydroxide (NaOH) under autoclaving conditions to improve glucose recovery. The effect of NaOH concentration (1%, 2%, 3%, and 4%) and autoclave temperature (110 °C, 120 °C, and 130 °C) was investigated based on the amount of glucose recovered. The optimal NaOH concentration and autoclave temperature were determined to be 2% and 110 °C, respectively, under which maximum glucose (36% and 35% in monthong and chanee peels, respectively) was recovered. Glucose recovery was improved by about 6-fold at the optimal pretreatment condition for both pretreated monthong and chanee when compared to the untreated durian peels. Scanning electron microscopy (SEM) showed great changes to the surface morphology of pretreated durian peel from the two cultivars. X-ray diffraction (XRD) analysis also revealed a rise in cellulose crystallinity index (CrIs) after pretreatment. A combination of mild NaOH concentration and autoclaving is a very effective pretreatment technique for maximum glucose recovery from durian peel.

Intergeneric Hybrid from Jatropha curcas L. and Ricinus communis L.: Characterization and Polyploid Induction.

Jatropha curcas L. (2n = 2× = 22) is increasingly attracting attention in the biodiesel industry for its oil. However, the cultivation of J. curcas L. is faced with numerous challenges unlike the cultivation of Ricinus communis L. (2n = 2× = 20), a closely related species. The generation of an intergeneric hybrid between J. curcas L. and R. communis L. was investigated. Intergeneric hybrids were produced by hand crossing. Immature embryos were rescued, in vitro, from the hybrid seeds and cultured on an enriched Murashige and Skoog (MS) medium for a month. The plantlets produced were grown in sterile peat moss in plastic pots and covered with polyethylene for 30 days, after which they were transferred into cement potted soil. The hybridity and the genuineness of the hybrids were successfully confirmed using randomly amplified polymorphic DNA (RAPD) markers. The number of branches, stem diameter, and leaf size of the F1 hybrids were similar to those of J. curcas L. while the plant height was similar to that of R. communis L. Young hybrids were treated with various concentrations (0%, 0.3%, 0.4%, and 0.5%) of colchicine to induce polyploids. The calli (JR6) treated with 0.3% colchicine recorded the highest tetraploid cell percentage (38.89%). A high tetraploid cell percentage (>50%) is significant in overcoming the problem of sterility after hybridization.

Combining Autoclaving with Mild Alkaline Solution as a Pretreatment Technique to Enhance Glucose Recovery from the Invasive Weed Chloris barbata.

Developing an optimum pretreatment condition to enhance glucose recovery assessed the potential of Chloris barbata, which is a common invasive weed in Thailand, as a feedstock for bioethanol production. Chloris barbata was exposed to autoclave-assisted alkaline pretreatment by using different sodium hydroxide (NaOH) concentrations (1% to 4%) and heat intensities (110 °C to 130 °C) that were dissipated from autoclaving. The optimum condition for pretreatment was determined to be 2% NaOH at 110 °C for 60 min. At this condition, maximum hydrolysis efficiency (90.0%) and glucose recovery (30.7%), as compared to those of raw C. barbata (15.15% and 6.20%, respectively), were observed. Evaluation of glucose production from 1000 g of C. barbata based on material balance analysis revealed an estimated yield of 304 g after pretreatment at the optimum condition when compared to that of raw C. barbata (61 g), an increase of five-fold. Structural analysis by the scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed the disruption of the intact structure of C. barbata and an increase in the cellulose crystallinity index (CrI), respectively. The results from this study demonstrate the efficiency of using C. barbata as a potential feedstock for bioethanol production.