Inoculum condition

Effects of Inoculum Conditions on Growth of Hairy Roots of Panax ginseng C.A. Meyer... 

Index Entries Panax ginseng transformed hairy root inoculum condition inoculum age root culture. 

Very few investigations have been carried out on the effect of inoculum conditions on hairy root cultures (11). In recent research of the root culture system, the inoculum studies have often focused on the physical structure and physiologic status of roots (14). Bhadra and Shanks (15) reported that the length of individual root tips was an important factor on growth, while the number of tips used in the inoculum had relatively little effect on Catharanthus roseus hairy root culture. 

Effect of Inoculum Conditions on P. ginseng Hairy Root... 

Fig. 1. Schematic of root segment preparation used for inoculum conditions of P. ginseng hairy root.

For scale-up of inoculum conditions of hairy root cultivation, a 1-L bioreactor (working volume of 800 mL) was used. This bioreactor had a height/diameter aspect ratio of 7.14. The bubble bioreactors had no internal mechanical agitation parts. The supplied aeration rate was 0.1 wm at the bottom by sparger. Each bioreactor was inoculated with 0.2-2.0 % (w/v) g fresh weight of hairy roots and cultured for 32 d. 

We investigated the effect of inoculum conditions such as the part, number, and length of root tips age of the hairy roots and size of inoculant on the growth and metabolite biosynthesis of P. ginseng C. A. Meyer hairy root culture. The growth of P. ginseng hairy roots in shake-flask cultures was found to vary depending on the inoculum conditions. The end part, whose apical meristem of root tip had been excised prior to inoculation,... 

Kawagoshi, Y., Hino, N., Fujimoto, A., Nakao, M., Fujita, Y., Sugimura, S., and Furu-kawa, K. 2005. Effect of inoculum conditioning on hydrogen fermentation and pH effect on bacterial community relevant to hydrogen production./. Biosci. Bioeng., 100, 524-530. 

FIGURE 27.12 Representative GC-MS mjz 85) chromatograms of saturated fractions for the SC (sterile control, top), NC (negative control, middle) and PC (positive control, bottom) of a Prudhoe Bay (PB) oil biodegradation series under the standard inoculum conditions. Peaks F, C, N, Pr, and Ph represent the most abundant 5 isoprenoids (famasane, trimethyl-Cis, norpristane, pristane, and phytane) in the oil. Sq represents the surrogate squalane. 

The highest xylitol production that we observed (31.6 g/1 Fig. 2a) was obtained using cells precultivated in YPD. This inoculum condition also showed the highest specific xylitol production rate 0.059 gxyiitoi/gceii h) and xylitol volumetric productivity Qp,... 

Ten percent of the resulting inoculum is then transferred to a 250 ml Erlenmeyer flask containing 50 ml of the medium employed above and the flask agitated a further 72 hours under the same conditions. One ml of the resulting inoculum is then employed for the inoculation of 10 ml of an aqueous medium containing, per 1,000 ml, 30 grams extraction... 

After seeding the nutrient medium with the preformed inoculum previously described, the mixture was subjected to agitation and aeration under aseptic conditions for 72 hours at 27°C to 28°C for the first 24 hours, then at 25°C to 26°C for the next 48 hours during this period, the pH was in the range of 6.4 to 6.8. Aeration was accomplished by cultivation under submerged conditions at an air flow rate of one volume of air per volume of medium per minute. After termination of the process, the mycelium was removed by filtration and the filtered broth found to contain 450 7of oleandomycin per ml of solution. 

Place the flask in a temperature-controlled shaker at 37 °C. The exponential growth phase will last from 2 to 24 hours after inoculation. The exact time and duration depend on the physiological condition of the inoculum. The data in Table 10.1 are plotted and a growth curve will be obtained for an exponentially growing culture. Figure 10.2 shows the typical growth curve obtained for a viable organism. 

This equation can always be satisfied with Xout = 0 so that the washout condition is always possible as a steady state. This steady state is achieved when there is no inoculum or when the flow rate is too high. A nontrivial solution with X ut > 0 requires that Fq, = 1 or... 

Laboratory experiments using natural consortia under defined conditions have particular value from several points of view. They are of direct environmental relevance, and their use minimizes the ambiguities in extrapolation from the results of studies with pure cultures. They provide valuable verification of the results of studies with pure cultures and make it possible to evaluate the extent to which the results of such studies may justifiably be extended to the natural environment. It should be appreciated, however, that in some cases the habitats from which the inoculum was taken might already have been exposed to xenobiotics so that natural enrichment (preexposure) could already have taken place. This has been discussed in Chapter 4. 

The importance of including soil-based parameters in rhizosphere simulations has been emphasized (56). Scott et al. u.sed a time-dependent exudation boundary condition and a layer model to predict how introduced bacteria would colonize the root environment from a seed-based inoculum. They explicitly included pore size distribution and matric potential as determinants of microbial growth rate and diffusion potential. Their simulations showed that the total number of bacteria in the rhizosphere and their vertical colonization were sensitive to the matric potential of the soil. Soil structure and pore size distribution was also predicted to be a key determinant of the competitive success of a genetically modified microorganism introduced into soil (57). The Scott (56) model also demonstrated that the diffusive movement of root exudates was an important factor in determining microbial abundance. Results from models that ignore the spatial nature of the rhizosphere and treat exudate concentration as a spatially averaged parameter (14) should therefore be treated with some caution. 

While the temperature and pressure conditions and inoculum usage may be practical, the reaction time, the investigated scale and the discontinuous nature of the process contribute to the difficulty of using this process for pretreatment operations. However, in cases where low throughput is needed, such as in the post-treatment of exhaust gases, this process would probably become a candidate to be considered. 

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