Enzyme use and production in industrial biotechnology

This chapter demonstrates the bioprocess strategies involved in the application and production of enzymes from an industrial view point. Moreover, bottlenecks in enzyme production and novel strategies to overcome the barriers are demonstrated here. Enzymes are produced from different sources of microorganisms and mostly all biological reactions happen due to the help of enzymes within a very short time. The different uses of enzymes are discussed in this chapter. </jats:p

Effect of Temperature on the Cannibalistic Behavior of Bacillus subtilis▿

Bacillus subtilis resorts to cannibalism to delay sporulation under severe nutritional limitation. We report the effect of temperature on the dynamics of cannibalism demonstrated by B. subtilis. A model consisting of a delay differential equation may explain the effect of temperature on the dynamics of cannibalism

Quantification of metabolically active biomass using Methylene Blue dye Reduction Test (MBRT): measurement of CFU in about 200 s

Quantification of viable cells is a critical step in almost all biological experiments. Despite its importance, the methods developed so far to differentiate between viable and non-viable cells suffer from major limitations such as being time intensive, inaccurate and expensive. Here, we present a method to quantify viable cells based on reduction of methylene blue dye in cell cultures. Although the methylene blue reduction method is well known to check the bacterial load in milk, its application in the quantification of viable cells has not been reported. We have developed and standardized this method by monitoring the dye reduction rate at each time point for growth of Escherichia coli. The standard growth curve was monitored using this technique. The Methylene Blue dye Reduction Test (MBRT) correlates very well with Colony Forming Units (CFU) up to a 800 live cells as established by plating. The test developed is simple, accurate and fast (200 s) as compared to available techniques. We demonstrate the utility of the developed assay to monitor CFU rapidly and accurately for E. coli, Bacillus subtilis and a mixed culture of E. coli and B. subtilis. This assay, thus, has a wide applicability to all types of aerobic organisms.© Elsevie

Algorithms for computing diffuse reflection paths in polygons

Let s be a point source of light inside a polygon P of n vertices. A polygonal path from s to some point t inside P is called a diffuse reflection path if the turning points of the path lie on polygonal edges of P. We present three different algorithms for computing diffuse reflection paths from s to t inside P. For constructing such a path, the first algorithm uses a greedy method, the second algorithm uses a transformation of a minimum link path, and the third algorithm uses the edge-edge visibility graph of P. The first two algorithms are for polygons without holes, and they run in O(n + k log n) time, where k denotes the number of reflections in the path. The third algorithm is for both polygons with or without holes, and it runs in O(n 2) time. The number of reflections in the path produced by this algorithm can be at most 3 times that of an optimal diffuse reflection path. The problem of computing a diffuse reflection path between two points inside a polygon has not been considered in the past