Converting lignin derived phenolic aldehydes into microbial lipid by Trichosporon cutaneum.

Lignin is one of the major components of lignocellulose biomass and chemically degrades into phenolic aldehydes including 4-hydroxybenzaldehyde, vanillin, and syringaldehyde. No lipid accumulation from the phenolic aldehydes by oleaginous microbes had been succeeded. Compared with vanillin and syringaldehyde, T. cutaneum ACCC 20271 have better tolerance to 4-hydroxybenzaldehyde. 4-Hydroxybenzaldehyde was found to be able as the substrate for lipid accumulation, while vanillin and syringaldehyde were only converted to less toxic phenolic alcohols and acids without observable lipid accumulation, perhaps due to the space shelling of methoxyl group(s) in the structures. A long term fed batch fermentation of 4-hydroxybenzaldehyde accumulated 0.85 g L-1 of lipid, equivalent to 0.039 g lipid per gram of 4-hydroxybenzaldehyde substrate, approximately 3.7 folds greater than the control without 4-hydroxybenzaldehyde addition. The fatty acid composition well met the need for biodiesel synthesis. The preliminary pathway from 4-hydroxybenzaldehyde to lipid was predicted. This study took the first experimental trial on utilizing phenolic aldehydes as the sole carbon sources for microbial lipid accumulation by T. cutaneum ACCC 20271.

Converting Chemical Oxygen Demand (COD) of Cellulosic Ethanol Fermentation Wastewater into Microbial Lipid by Oleaginous Yeast Trichosporon cutaneum.

Cellulosic ethanol fermentation wastewater is the stillage stream of distillation column of cellulosic ethanol fermentation broth with high chemical oxygen demand (COD). The COD is required to reduce before the wastewater is released or recycled. Without any pretreatment nor external nutrients, the cellulosic ethanol fermentation wastewater bioconversion by Trichosporon cutaneum ACCC 20271 was carried out for the first time. The major components of the wastewater including glucose, xylose, acetic acid, ethanol, and partial of phenolic compounds could be utilized by T. cutaneum ACCC 20271. In a 3-L bioreactor, 2.16 g/L of microbial lipid accumulated with 55.05% of COD reduced after a 5-day culture of T. cutaneum ACCC 20271 in the wastewater. The fatty acid composition of the derived microbial lipid was similar with vegetable oil, in which it could be used as biodiesel production feedstock. This study will both solve the environmental problem and offer low-cost lipid feedstock for biodiesel production.

[Clinical observation of hidden tension suture with absorbable thread].

OBJECTIVE: To observe the operative technique and clinical effects of hidden tension suture after tibiofibular fracture fixation with absorbable thread. METHODS: From October 2003 to October 2008, 203 patients (220 sides) with tibiofibular fracture underwent hidden tension suture (test group, 102 cases of 112 sides) and the common interrupted suture (control group, 101 cases of 108 sides), including 179 males and 24 females with an median age of 36 years (3-75 years). Fracture was caused by traffic accident in 170 cases, by heavy bruise in 21 cases, and by falling from height in 12 cases. There were 186 cases of single-side fracture, and 17 cases of double-side fracture. Of them, 127 sides were closed fracture, and 93 sides were open fracture (including 38 sides of type I, 45 sides of type II, and 10 sides of type IIIA according to Gustilo classification for the open fracture). The locations were upper tibia in 55 sides, middle tibia in 126 sides, and lower tibia in 39 sides. The X-ray films showed that there were transverse fractures in 65 sides, oblique fractures in 53 sides, spiral fractures in 45 sides, and comminuted fractures in 57 sides. No blood vessel injury, osteofascial compartment syndrome and pressure syndrome were observed. The time from injury to operation was 2 hours to 7 days with an average of 2 days. Of 220 sides, 45 sides were fixed by interlocking nails, others by internal steel plate. RESULTS: In control group, healing by first intention was achieved in 70 cases (69.3%) and healing by secondary intention in 31 cases (30.7%); in test group, healing by first intention was achieved in 93 cases (91.2%) and healing by secondary intention in 9 cases (8.8%); and showing significant difference (P < 0.05). All patients were followed up for 6 months to 2 years (average 9 months). No complication occurred in test group, and scar was obvious in the control group. CONCLUSION: The hidden tension suture with absorbable thread can be a good alternative for the incision healing after tibiofibular fracture fixation. It deals with the problems of the incision tension and difficult-to-suture, and is good for the incision healing after operation.