Water hyacinth is a rapidly growing troublesome aquatic weed plant, which causes eutrophication in water bodies and irreversible damage to the ecological system. In this work, we have investigated the water hyacinth biomass (WHB) hydrolysis efficacy of dilute alkaline (DA) pretreatment followed by biological pretreatment with white-rot fungus Alternaria alternata strain AKJK-2. The effectiveness of the dilute alkaline (DA) and biological pretreatment process on WHB was confirmed by using X-ray Diffraction (XRD) and Fourier Transform Infrared Spectrophotometer (FTIR), and was further visualized by Scanning Electron Microscope (SEM) and Confocal Laser Scanning Microscopy (CLSM). XRD spectra showed the increase in the crystallinity of pretreated samples, attributed to the elimination of amorphous components as lignin and hemicellulose. FTIR peak analysis of pre-treated WHB showed substantial changes in the absorption of cellulose functional groups and the elimination of lignin signals. Scanning electron microscopy (SEM) images showed firm, compact, highly ordered, and rigid fibril structures without degradation in the untreated WHB sample, while the pretreated samples exhibited loose, dispersed, and distorted structures. XRD indices (Segal, Landis, and Faneite), and FTIR indices [Hydrogen bond intensity (HBI); Total crystallinity index (TCI); and Lateral order crystallinity (LOI)] results were similar to the aforementioned results, and also showed an increase in the crystallinity both in alkaline and biological pretreatments. Alkaline pretreated WHB, with these indices, also showed the highest crystallinity and a crystalline allomorphs mixture of cellulose I (native) and cellulose II. These results were further validated by the CLSM, wherein fluorescent signals were lost after the pretreatment of WHB over control. Overall, these findings showed the significant potential of integrated assessment tools with chemical and biological pretreatment for large-scale utilization and bioconversion of this potential aquatic weed for bioenergy production.

The fruits of Prosopis juliflora have the potential to be raw material in the production of bioethanol due to its high carbohydrate and fiber content, and its high productivity in arid localities. P. juliflora fruits were characterized chemically, its sun drying kinetics was modeled and 2 physicochemical pretreatments were evaluated. The fruits showed a moisture content of 12.51% on a wet basis (wb), 14.84% protein, 2.27% fat, 20.15% fiber, 58.49% Nitrogen Free Extract (NFE) and 4.25% of ash, on dry basis (db). The prediction sun drying of Faneite-Suárez model was the best, within the range of prevailing weather conditions. The acid pretreatment (6% of sulfuric acid, for 20 min, at 121 ° C) got the highest content of reducing sugars, 37.85%. The evaluated fruits can be used in the production of bioethanol through a technically feasible and sustainable processing route.