Friday, September 19, 2014
YOLO COUNTY NEWS
99 CENTS

Sequencing opens window on wine’s microbial terroir

By
From page A5 | December 05, 2013 |

It’s widely accepted that terroir — the unique blend of a vineyard’s soils, water and climate — sculpts the flavor and quality of wine.

Now, a new study led by UC Davis researchers offers evidence that grapes and the wines they produce are also the product of an unseen but fairly predictable microbial terroir, itself shaped by the climate and geography of the region, vineyard and even individual vine.

Results from DNA sequencing revealed that there are patterns in the fungal and bacterial communities that inhabit the surface of wine grapes, and these patterns are influenced by vineyard environmental conditions. The findings appear online this week in the Early Edition of the Proceedings of the National Academy of Sciences.

“The study results represent a real paradigm shift in our understanding of grape and wine production, as well as other food and agricultural systems in which microbial communities impact the qualities of the fresh or processed products,” said David Mills, a microbiologist in the department of viticulture and enology and department of food science and technology.

He noted that further studies are needed to determine whether these variations in the microbial communities that inhabit the surface of the grapes eventually produce detectable differences in the flavor, aroma and other chemically linked sensory properties of wines.

The study co-authors suggest that by gaining a better understanding of microbial terroir, growers and vintners may be able to better plan how to manage their vineyards and customize wine production to achieve optimal wine quality.

To examine the microbial terroir, the researchers collected 273 samples of grape “must,” — the pulpy mixture of juice, skins and seeds from freshly crushed, de-stemmed wine grapes.

The must samples were collected right after crushing and mixing from wineries throughout California’s wine-grape growing regions during two separate vintages. Each sample, containing grapes from a specific vineyard block, was immediately frozen for analysis.

The researchers used a DNA sequencing technique called short-amplicon sequencing to characterize the fungal and bacterial communities growing on the surface of the grapes and subsequently appearing in the grape must samples.

They found that the structure of the microbial communities varied widely across different grape growing regions. The data also indicated that there were significant regional patterns of both fungal and bacterial communities represented in Chardonnay must samples. However, the Cabernet Sauvignon samples exhibited strong regional patterns for fungal communities but only weak patterns for bacterial communities.

Further tests showed that the bacterial and fungal patterns followed a geographical axis running north-south and roughly parallel to the California coastline, suggesting that microbial patterns are influenced by environmental factors.

Taken together, these and other results from the study reveal patterns of regional distributions of the microbial communities across large geographical scales, the study co-authors reported.

They noted that it appears that growing regions can be distinguished based on the abundance of several key groups of fungi and bacteria, and that these regional features have obvious consequences for both grapevine management and wine quality.

Collaborating with Mills were graduate student Nicholas Bokulich of the viticulture and enology department, John Thorngate of Constellation Brands Inc., which supported the study through sample and metadata collection, and Paul Richardson, CEO of MicroTrek Inc., a company founded to provide microbial mapping services for vintners.

— UC Davis News

Comments

comments

.

News

UC to create $250 million venture capital fund

By San Francisco Chronicle | From Page: A1

 
Telling tales, on ‘Davisville’

By Enterprise staff | From Page: A3

Volunteers sought to make veggie bags

By Enterprise staff | From Page: A3

 
Storyteller will draw on music, dance

By Enterprise staff | From Page: A3

Woodland Healthcare offering flu shots

By Enterprise staff | From Page: A3

 
Putah Creek Bike Path to close temporarily

By Enterprise staff | From Page: A3

 
Little Free Libraries open at Montgomery

By Anne Ternus-Bellamy | From Page: A3

Project Linus seeks donations

By Enterprise staff | From Page: A3

 
Rabid bat found at Holmes Junior High

By Enterprise staff | From Page: A3

Students invited to apply for Blue & White grants

By Enterprise staff | From Page: A3

 
Halloween costume sale benefits preschool

By Enterprise staff | From Page: A3

Register to vote by Oct. 20

By Enterprise staff | From Page: A4

 
Free workout class set at library

By Special to The Enterprise | From Page: A4

Explorit: Lots of ways to be a volunteer

By Lisa Justice | From Page: A4 | Gallery

 
Sierra Club remembers longtime walker

By Special to The Enterprise | From Page: A4

DHS Classes of 1954 and 1955 will hold 60th reunion

By Enterprise staff | From Page: A4

 
Nonprofits can get DCN’s help

By Enterprise staff | From Page: A4

 
Need a new best friend?

By Enterprise staff | From Page: A5 | Gallery

Davis maps available at Chamber office

By Enterprise staff | From Page: A5

 
Reception benefits endangered gorillas

By Special to The Enterprise | From Page: A5

Sutter Farmers Market offers local goods

By Enterprise staff | From Page: A8 | Gallery

 
Wolk applauds approval of stronger rules for olive oil

By Special to The Enterprise | From Page: A8

Davis hosts its own climate change rally

By Special to The Enterprise | From Page: A8

 
Qigong classes available for heart health

By Enterprise staff | From Page: A9

.

Forum

Educate homeless with dogs

By Letters to the Editor | From Page: A6, 1 Comment

 
Cheers and Jeers: Not the end of the rainbow

By Our View | From Page: A6

Tom Meyer cartoon

By Debbie Davis | From Page: A6

 
Return to previous plan

By Letters to the Editor | From Page: A6

Save the ‘pine cone place’

By Letters to the Editor | From Page: A6

 
Affirm our community values

By Letters to the Editor | From Page: A6

Project has safety risks

By Letters to the Editor | From Page: A6

 
Learn more about Paso Fino

By Letters to the Editor | From Page: A6

.

Sports

Aggies’ new energy could be scary for Big West

By Bruce Gallaudet | From Page: B1

 
No rest for the weary: Aggie TE Martindale busy on and off the field

By Bruce Gallaudet | From Page: B1 | Gallery

Devils hope the light bulb goes off at Edison

By Enterprise staff | From Page: B1

 
River Cats and Giants sign two-year deal

By Enterprise staff | From Page: B1

Take Zona and Bama this week

By Bob Dunning | From Page: B2

 
Mustangs are no match for DHS boys in water polo

By Enterprise staff | From Page: B2

A’s slide continues as Rangers sweep

By The Associated Press | From Page: B8

 
.

Features

.

Business

Redesigned 2015 Escalade remains breed all its own

By Ann M. Job | From Page: B3 | Gallery

 
.

Obituaries

Carol L. Walsh

By Special to The Enterprise | From Page: A4

 
.

Comics

Comics: Friday, September 19, 2014

By Creator | From Page: A10