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40 WINES&VINES July 2016 WINEMAKING PRACTICAL WINERY & VINEYARD to find wine LAB that possess this characteristic. Fruity aromas that are desired in red wines are affected by MLF. The esterase enzymes that mod- ify the composition of esters are responsible, as they modify the esters comprising the fruity com- ponent. 1,29 The concentration of ethyl esters of fatty acids and acetate esters of higher alcohol varies according to the wine LAB strain and grape variety. 21 Interactions between yeast and lactic acid bacteria—as well as their effect on MLF—play a role in the modification of aromas. 1 The sensory qualities of wines are not limited to volatile molecules, as wine LAB transform other com- ponents that are directly (or in combination with other compo- nents) involved in structuring the taste and color of wine. Genetic approaches that ex- ploit gene expression and protein synthesis, coupled with sensory and chemical analysis, may lead to selected wine LAB strains ca- pable of modifying both taste and aroma. These genetic approaches may help to more logically exploit the diversity of O. oeni. 3 In the must, the LAB micro- flora usually includes several Lac- tobacillus species, along with Pediococcus and O. oeni. In gen- e r a l , t h e h i g h e r t h e p H t h e greater the microbial diversity during alcoholic fermentation. Under these conditions, indige- nous wine LAB, not necessarily O. oeni, may carry out MLF. In some regions, Lactobacillus plantarum is present in equal or greater amounts than O. oeni and has manifested a large num- ber of genetic profiles. 6,30 Be- s i d e s i t s s t r o n g m a l o l a c t i c activity, L. plantarum may pos- sess a wide range of enzymatic activities with possible impacts on aroma profiles. 20 Pediococcus damnosus is the other species well represented in the wine environment. It is often found in wines with rather high pH, along with Lactobacillus sp. and O. oeni. As it has been identi- fied in most ropy wines, its pres- ence is considered undesirable. In reality, only certain strains of P. damnosus are responsible for this spoilage, and they are easily iden- tified through PCR. Little research has been published on the possi- bility of using these organisms as wine LAB starter cultures. A study in which indigenous strains of P. damnosus dominate a starter culture of O. oeni and con- duct the MLF shows that it is very capable of surviving in wine. 18 The technique of co-inocula- tion of the fermenting must with yeast and selected wine LAB is not widely used, despite its ad- vantages. In addition to reducing the time required for MLF, the procedure affects the sensory profile of a wine. There are complex interactions between the yeast and the must composition, so co-inoculation is not straightforward. Success is closely tied to having an experi- enced winemaker with an intimate familiarity with the idiosyncrasies of the winery. Scientists who at- tempt to describe these interactions in terms of gene expression may provide some interpretations. 27 An alternative to using conven- tionally selected wine LAB starter cultures is to use an immobilized form of the bacteria. In this pro- cedure, the wine LAB are bound to a solid support and are either placed into reactors with circulat- ing wine or are added directly to www.flextankusa.com 877 407 3348 sales@flextankusa.com Proudly designed and manufactured in the USA. Tanks are manufactured in and ship from Vancouver WA 98682 by You asked for Bigger Call Mike Humes direct at 360 241 1832 or John Sm Smeaton direct at 706 714 266 2662 to learn more about these these unique and cost effective tanks an tanks and to take advantage of the introdu the introductory pricing. Flextank's Apollo has been acclaimed for producing medal winning wines on four continents since its 2011 introduction. We have had many requests for larger sizes and we now introduce "Orion" and "Galaxy" with 2000 and 5000 liter capacities. Introductory pricing of $1800 and $2900 respectively represent outstanding Egg Tank value compared to alternatives at up to $10 per liter. I N T R O D U C I N G Superior Solutions for Professional Winemaking Visit our website and get the full story The identification of malolactic bacteria species, the genetic typing of wine LAB strains and the genetic identification of undesirable organisms has occurred, but improvements to wine LAB starter cultures have remained limited.