Researchers at the Mississippi State University and University of Wisconsin-Madison have discovered bacteria in panda feces, which can aid in the process of breaking down the tough plant biomass into fermentable sugars, the precursors of bioethanol.

The researchers have identified more than 40 microbes living in the guts of giant pandas at the Memphis Zoo. These microbes release potent enzymes for digesting tough plant materials, also called lignocellulose. The researchers believe that panda gut enzymes are very efficient in breaking down lignocellulose as the time from eating bamboo biomass to defecation is comparatively short in the panda.

Scientists have been developing the technology for efficiently turning lignocellulosic biomass like agricultural waste, grasses and other plant materials not intended for food into biofuels. Enzymatic efficiency is a key to this conversion, hence, the focus on panda gut microbial enzymes.

The study, presented at the 246th National Meeting & Exposition of the American Chemical Society (ACS), also found bacteria that can turn sugars into oils and fats, which may be used for biodiesel production. Either the bacteria themselves or the enzymes in them could be part of the conversion process.

A new comparative emission study led by researchers at the US Environmental Protection Agency has presented new evidence that exhausts from biodiesel are less mutagenic than those from petroleum diesel and mutagenic activity is mostly associated with pollutants called polycyclic aromatic hydrocarbons (PAH).

The researchers analyzed the particles released by a diesel engine that ran on petroleum diesel and soy-based biodiesel where the biodiesel accounted for 20, 50 or 100 percent of the fuel. The mutagenic property of the recovered particles was evaluated in various strains of the bacterium Salmonella. Data from a strain which responds to PAH-type mutagenicity were processed to measure mutagenicity of the petroleum disesel and biodisel particles. Computed mutagenic emission factors for the biodiesel were 3 to 8 times less than that of petroleum diesel.

The present results contradict some published findings by other investigators. Thus, the new study calls for a deeper look into the health impacts of the two diesel types. This study was presented at the 246th National Meeting & Exposition of the American Chemical Society (ACS) along with other papers dealing with toxicology of alternate fuels.

University of Cincinnati researchers were able to extract oil from waste coffee grounds collected from a campus cafe and converted it to biodiesel. After oil extraction, they produced activated carbon from the dried coffee grounds and used it as filter material to remove the impurities in crude biodiesel.

An estimated one million metric tons of waste coffee grounds is generated in the U.S. alone, and most of this waste is dumped into landfills. The promising discovery reported at the 246th National Meeting & Exposition of the American Chemical Society (ACS) would not only open landfill space, but it also offers an alternative source of biodiesel without compromising the food supply. Biodiesel is typically manufactured from food crops such as corn and soybean.

The researchers reported that the highest oil yield from waste coffee grounds was almost 20 percent, and the biodiesel made from this oil has met industry standards. The efficiency of coffee grounds-derived activated carbon as purification material for crude biodiesel was slightly lower compared with commercial purification products. With more opportunities for improvement, UC researchers find it as a promising alternative material for biodiesel purification, considering the cost of commercial filters. Future research will focus on improving its purification efficiency.

Clemson University researchers are developing the right combination of enzymes from bacterial and fungal sources to hasten the utilization of plant biomass as raw material for biofuel production.

Conversion of plant biomass into cost-competitive biofuels requires an efficient way to break down the tough cellulose and xylan molecules bound in plant cell walls. These complex molecules can be enzymatically degraded into simple sugars which can be fermented into ethanol. Scientists aim to tap the natural abilities of bacteria and fungi in decomposing plant materials to aid in this process.

A research at Clemson University involves identifying the right bacteria and fungi and the right enzymes that will break down the cellulose and xylan in switchgrass and waste paper to release fermentable plant sugars. As fungi and bacteria work additively as a community, research is focused on developing an "enzyme cocktail." This work aims to reduce the cost of making ethanol from plant biomass.