The present study demonstrates the ability to produce green biocellulose nanofibers using the renewable resources of agriculture residues. Locally grown wheat straws (WS) were hydrolyzed under different conditions. Their hydrolysates were utilized to produce the nanofibers in separate hydrolysis fermentation process by Gluconacetobacter xylinus strain bacterium. Highest biocellulose production of ~10.6 g/L was achieved with samples that were enzymatically hydrolyzed. Moreover, acidic hydrolyzed WS produced up to 9.7 g/L, with total sugar concentrations in culture media of 43 g/L. Generally, enzymatic hydrolysis of WS resulted in more total sugar concentration than the acidic hydrolysis (i.e., 52.12 g/L), while water hydrolysis produced the least. This can be related to utilizing Xylanase in addition to Cellulase and Beta-glucosidase that helps to hydrolyse WS dry basis of cellulose and hemicelluloses. Sugar mixtures produced under all hydrolysis conditions were mainly composed of glucose and xylose with average percentages of 56 and 28 %, respectively. Acidic hydrolysis at higher acid concentration, as well as soaking WS in the acidic solution for longer time, improved the total sugar concentration in the culture media by 18 %. Conducting thermal treatment at more intense conditions of higher temperature or heating time improved the total sugar produced with acidic hydrolysis. These conditions, however, resulted in further production of furfural, which considerably affected bacterial cells proliferation. This resulted in lowest sugar consumption in the range of 62-64 % that affected final BC production.

In the present study, the green Biocellulose Nanofibers (BC), a vitally emerging biomaterial, was produced by fermentation of wheat straw (WS), as a widely available agricultural waste, using. Two different fermentation methods were used; Separate Hydrolysis and Fermentation (SHF), and Simultaneous Saccharification and Fermentation (SSF). Different acidic and enzymatic WS pretreatment conditions were used to understand the effect of pretreatment conditions on BC production. Afterward, sugar hydrolsates were simultaneously or separately inoculated with Gluconacetobacter Xylinum bacterium (i.e., for SSF and SHF, respectively), at optimum production conditions in shake flasks for 7 days to produce the biocellulose nanofibers. BC productions of 9.7 g/L in SHF and 10.8 g/L in SSF were achieved when WS was pretreated with dilute acids. Enzymatic treatment of WS after acidic pretreatment increased sugars’ concentrations from the hydrolysis, which increased BC production in SHF to 10.6 g/L. However, enzymes in SSF broke cellulose I alpha linkage in BC and decreased its production compared to no enzymatic treatment. Results show that glucose extracted from WS (~55% of total sugars) was found essential for the cellular metabolism, while xylose (~28% of total sugars) was highly consumed during cells growth phase. Generally, increasing thermal treatment, time and temperature, resulted in increasing furfural concentration. This observed to inhibits bacterial cells growth and leads to lower nanofibers yield when exists at concentration higher than 1 g/L threshold. In general, results obtained in the present study demonstrate the ability of utilizing agricultural wastes in the fermentation production of BC. Such a step is expected to eliminate cost of expensive pure sugars as a carbon source in the fermentation. Also the study shows an improved production yield by using effective fermentation techniques as SSF compared to classical methods used in literature.

In the present study, the green Biocellulose Nanofibers (BC), a vitally emerging biomaterial, was produced by fermentation of wheat straw (WS), as a widely available agricultural waste, using. Two different fermentation methods were used; Separate Hydrolysis and Fermentation (SHF), and Simultaneous Saccharification and Fermentation (SSF). Different acidic and enzymatic WS pretreatment conditions were used to understand the effect of pretreatment conditions on BC production. Afterward, sugar hydrolsates were simultaneously or separately inoculated with Gluconacetobacter Xylinum bacterium (i.e., for SSF and SHF, respectively), at optimum production conditions in shake flasks for 7 days to produce the biocellulose nanofibers. BC productions of 9.7 g/L in SHF and 10.8 g/L in SSF were achieved when WS was pretreated with dilute acids. Enzymatic treatment of WS after acidic pretreatment increased sugars’ concentrations from the hydrolysis, which increased BC production in SHF to 10.6 g/L. However, enzymes in SSF broke cellulose I alpha linkage in BC and decreased its production compared to no enzymatic treatment. Results show that glucose extracted from WS (~55% of total sugars) was found essential for the cellular metabolism, while xylose (~28% of total sugars) was highly consumed during cells growth phase. Generally, increasing thermal treatment, time and temperature, resulted in increasing furfural concentration. This observed to inhibits bacterial cells growth and leads to lower nanofibers yield when exists at concentration higher than 1 g/L threshold. In general, results obtained in the present study demonstrate the ability of utilizing agricultural wastes in the fermentation production of BC. Such a step is expected to eliminate cost of expensive pure sugars as a carbon source in the fermentation. Also the study shows an improved production yield by using effective fermentation techniques as SSF compared to classical methods used in literature.