The effect of VB added into the culture medium on the nucleic acid was better than the yeast extracts.

Mr. Koum: For us, it's about staying independent.

：对我们来说，关键是保持独立。

Mr. Koum: To be fair to Mark, I don't understand a whole lot about Facebook's internal metrics and statistics and how the company works and different ways to generate revenue.

：实话实说，我对Facebook的内部指标和统计数据以及该公司如何运作、产生收入的种种来源真的不是很清楚。

The app is so popular, WhatsApp CEO Jan koum revealed earlier this month it has more users than twitter, which reported 200 million-plus members last December.

首席执行官杨•库姆上月早些时候透露，WhatsApp的用户数已赶超Twitter，而后者早在去年12月就号称用户数已经突破了2亿。

Jan Koum, WhatsApp co-founder, said protecting private communication was a core value at WhatsApp, partly because of his own experience growing up in the Soviet Union.

WhatsApp联合创始人简•库姆（Jan Koum）表示，保护私人通信是WhatsApp的核心价值观之一，部分原因是他在苏联长大的经历。

But on his LinkedIn page, the 37-year-old Koum flies more under-the-radar.

但在LinkedIn的个人主页上，现年37岁的库姆有着更多不引人注目头衔和经历。

Rather than be absorbed into Facebook's business, Mr. Koum sees WhatsApp functioning as a separate arm that will help the social network diversify its revenue streams as it grows.

库姆认为今后WhatsApp将单独作为Facebook的一个实体继续运营，帮助Facebook在成长的同时实现收入来源的多元化。

Mr. Koum: It was all his idea.

：这完全是他的主意。

Still, Acton and Koum's late-blooming strategy worked.

不过，阿克顿和库姆大器晚成的战略行之有效。

Before that, he spent three years at Apple AAPL 0.39% and over 11 years at Yahoo, where he met WhatsApp CEO and cofounder Jan Koum and eventually became the company's vice president of engineering.

在此之前，他在苹果（Apple）干了三年，在雅虎干了11年多。阿克顿在雅虎结识了WhatsApp首席执行官兼联合创始人简o库姆，并最终成为WhatsApp公司负责工程设计的副总裁。

Mr. Koum told The Wall Street Journal last December that WhatsApp has 'no plans to sell, IPO, exit,' or get new funding.

Koum去年12月份向《华尔街日报》（The Wall Street Journal）表示，WhatsApp没有出售、上市、退出或筹资的计划。

Jan Koum, WhatsApp chief executive and the guy who just agreed to sell his company to Mr. Zuckerberg for$ 19 billion, is also addressing the congress, along with a stable of chiefs of the world's biggest telecom companies.

WhatsApp首席执行长库姆（Jan Koum）也与世界最大科技公司的一众老板们一道出席大会；库姆刚刚以190亿美元向扎克伯格出售了WhatsApp。

WhatsApp will continue to operate independently and retain its brand, while co-founder and CEO Jan Koum will join Facebook's board, bringing the total number of members to nine.

WhatsApp将继续独立运营，并保留自己的品牌，WhatsApp的联合创始人兼首席执行长Jan Koum将加入Facebook董事会，这使得Facebook董事会的成员增加到九人。

Privacy was particularly important to Mr. Koum, who grew up in a communist country with a secret police.

Koum是在一个有秘密警察的共产主义国家长大的，隐私对他来说尤为重要。

Mr. Koum: It was very difficult for him to find a good way that would make us be interested in a conversation.

：对马克来说，要找到一个令我们感兴趣的对话切入点非常难。

Talks with Zuckerberg about a potential WhatsApp acquisition began heating up in early February, when Zuck-as he is known to tech insiders-presented Acton and Koum with a hard number.

早在今年二月初，同扎克伯格关于可能收购WhatsApp的谈判就开始升温。扎克伯格向阿克顿和库姆开出了一个确切的数字——高科技界人士都知道，这是他的一贯做法。

These differences have been a continual topic of discussion for the two men as they developed a friendship over the past two years and ultimately negotiated the deal that would make Mr. Koum a multi-billionaire and bring his 55-person startup inside the social network.

上述差异一直是这两人间不断讨论的话题。他们在过去两年间结成友谊，并最终谈判达成前述交易。这宗交易足以令库姆成为一名亿万富豪，并将这家共有55名员工的初创企业并入Facebook这张社交网络。

Mr. Zuckerberg said he and Mr. Koum first discussed the deal on a Sunday evening less than two weeks ago.

扎克伯格表示，他与Koum首次讨论这笔交易是在不到两周前的一个周日的晚上。

Below are edited excerpts of the interview with Mr. Koum:

以下是经过编辑的访谈内容：

Jan Koum, WhatsApp's co-founder and chief executive, has resisted advertising and built a mobile service that makes money from 99-cent subscriptions.

WhatsApp的联合创始人兼首席执行长（CEO）库姆（Jan Koum）一直拒绝在应用程序内引入广告，其主要收入就是用户支付的每年99美分的使用费。

Jan Koum co-founded WhatsApp along with Brian Acton, a former colleague at Yahoo, and is the mobile-messaging company's chief executive.

简•库姆和他当年在雅虎（Yahoo）的同事布莱恩•埃克顿（Brian Acton）共同创建了WhatsApp，并担任这家移动消息应用公司的首席执行长。