Biorefineries using waste – production of energy and chemicals from biomasses by micro-organisms - Biomass as Energy Source: Resources, Systems and Applications - page 241

of the world's bioenergy production, this proportion has to make room for more sophisticated
and economically feasible approaches. The microbial biotechnology is one of the most impor-
tant of these solutions since it is the nature's way and the potential is huge offering practically
limitless sources with respect to the biodegradation and circulation of wastes and other biomass
sources.
13.7.3 Starch and other saccharides from food industry by-streams and agriculture
In food industries, a considerable amount of unused parts of the raw materials of either plant
or animal origin, as well as process wastes, cleaning and washing liquids, unsuccessful product
rounds, by-products, and several other commodities constitute a fruitful base for biorefinery
operations. The substances contain such saccharides as starch, lactose, maltose, and fractions of
the sugar industries. These materials provide the bioprocesses an excellent starting point. It is
often only a matter of redirecting the focus of industrial production from solely the food products
into the direction of balanced multiproduct industries.
Total amount of waste biomasses in the world has been estimated to reach two billion tonnes
annually (Gressel and Zilberstein, 2007). The grain crops are required for the food production for
the population directly, and as a feed supply for the animal production. It has been a controversial
issue whether this biomaterial could be used as feedstock for biotechnological production of fuels
and chemicals. In fact, the crops always produce plentiful wastes and by-products, which are
an adequate source for bioengineering purposes. In the huge effort to complement the needs for
global human nutrition, about a half of the biomasses is wasted in anyway. For example, straw is
often being burnt or slowly degraded in the soil in which processes much of the energy value is
being lost. As a feed components of the ruminants, the straw cannot be fully exploited because the
use by the animal is restricted or limited by a minor component, lignin. Its presence is preventing
the complete biodegradation of hemicellulose or cellulose by the rumen bacteria.
Improving the yields of agricultural biotechnologies is highly dependent on the development
of hydrolysis processes. Even though the entire process of the grain utilization by the cattle is
low in overall efficiency, the liberated chemical energies are enough for the vast production of
milk and meat, hides, skulls and bones, and manure during and after the life-span of the animals.
We should also not forget the volatiles emitted by the animals resulting from the microbial action
in their intestines. This outflow of greenhouse gases is paid a major attention to in New Zealand
for example, where new methods are developed for the elimination of this climatological effect.
This influence of domestic animals closely equals to the emissions of the industrial production
in New Zealand. Likewise, with respect to the water qualities, former Finnish president Tarja
Halonen has emphasized the need for effective treatment of agricultural wastewaters caused by
the animal production. The PMEU method has been developed for the effective monitoring of the
water quality (Hakalehto et al. , 2011a).
13.7.4 Industrial waste biomasses
Enormous amounts of biomass are processed in the paper and pulp industries. The liquors, process
waters, wood wastes such as bark or saw dust, and pooled wastewaters offer a plentiful supply
of cellulose, hemicellulose and lignin-containing raw materials. This reservoir is somewhat more
challenging as a starting material for bio-industries. For example, waxes and phenolic compounds
may restrict or inhibit the required bioactivities. On the other hand, the forest industries possess
facilities for transport, storage and pretreatment of wood. Therefore, these industrial plants could
be converted from “one product entities” into biorefineries consisting of numerous product lines
and processes in the same area. The treatments of the fibrous rawmaterials intomore readily usable
sources should be in the scope of their research activities. In this modification of various wood
fragments and lignocellulosic wastes microbes offer extended options. Effective hydrolysis is a
pre-requisite for a successful process. Considerable amount of research has been directed towards
wood-derivedmaterials and their processing for bio-industries since these materials constitute one