Metabolism of Multiple Aromatic Compounds in Corn Stover Hydrolysate by Rhodopseudomonas palustris.

Lignocellulosic biomass hydrolysates hold great potential as a feedstock for microbial biofuel production, due to their high concentration of fermentable sugars. Present at lower concentrations are a suite of aromatic compounds that can inhibit fermentation by biofuel-producing microbes. We have developed a microbial-mediated strategy for removing these aromatic compounds, using the purple nonsulfur bacterium Rhodopseudomonas palustris. When grown photoheterotrophically in an anaerobic environment, R. palustris removes most of the aromatics from ammonia fiber expansion (AFEX) treated corn stover hydrolysate (ACSH), while leaving the sugars mostly intact. We show that R. palustris can metabolize a host of aromatic substrates in ACSH that have either been previously described as unable to support growth, such as methoxylated aromatics, and those that have not yet been tested, such as aromatic amides. Removing the aromatics from ACSH with R. palustris, allowed growth of a second microbe that could not grow in the untreated ACSH. By using defined mutants, we show that most of these aromatic compounds are metabolized by the benzoyl-CoA pathway. We also show that loss of enzymes in the benzoyl-CoA pathway prevents total degradation of the aromatics in the hydrolysate, and instead allows for biological transformation of this suite of aromatics into selected aromatic compounds potentially recoverable as an additional bioproduct.

The delivery of radical radiotherapy to the bladder and pelvis in node-positive (N1) bladder cancer: a five patient case series.

In the UK over 10,000 new cases of bladder cancer were diagnosed in 2012, making it the seventh most common cancer in the UK. For those with advanced disease at presentation, prognosis is poor. Disease presenting with one pathological node (N1) is considered to be Stage 4 and is therefore considered the same as disease with widespread metastases. Pelvic lymph node dissection is considered standard when performing radical cystectomy; however, owing to potential toxicity, pelvic radiotherapy is not routine even when attempting radical treatment. We present five cases where radical treatment has been delivered to patients with node-positive bladder cancer. Treatment volumes included the whole bladder and bilateral pelvic nodes, and where it was felt appropriate, chemotherapy was delivered concurrently. Data has been collected by reviewing hospital notes including radiotherapy, volumes and dose distributions. Treatment was tolerated well with only minimal gastrointestinal and urinary symptoms reported. Three of the five patients had thrombocytopenia. This complication may be explained by the larger volume of radiation exposure. Local control appears to be good with all the patients having no pelvic relapse at the time of reporting. Two patients have relapsed with distant metastatic disease. No long-term side effects of therapy have been reported. Intensity-modulated radiotherapy techniques allow larger volumes to be treated owing to improved conformality and the resulting reduced toxicity. Treatment may be appropriate with both radical and adjuvant doses of radiation. More work is necessary to assess which patients would benefit and are most suitable for such treatment.

Effect of storage conditions on the stability and fermentability of enzymatic lignocellulosic hydrolysate.

To minimize the change of lignocellulosic hydrolysate composition during storage, the effects of storage conditions (temperature, pH and time) on the composition and fermentability of hydrolysate prepared from AFEX™ (Ammonia Fiber Expansion - a trademark of MBI, Lansing, MI) pretreated corn stover were investigated. Precipitates formed during hydrolysate storage increased with increasing storage pH and time. The precipitate amount was the least when hydrolysate was stored at 4 °C and pH 4.8, accounting for only 0.02% of the total hydrolysate weight after 3-month storage. No significant changes of NMR (Nuclear Magnetic Resonance) spectra and concentrations of sugars, minerals and heavy metals were observed after storage under this condition. When pH was adjusted higher before fermentation, precipitates also formed, consisting of mostly struvite (MgNH4PO4·6H2O) and brushite (CaHPO4·2H2O). Escherichia coli and Saccharomyces cerevisiae fermentation studies and yeast cell growth assays showed no significant difference in fermentability between fresh hydrolysate and stored hydrolysate.